Generalize README to the use case of using an already-defined proto
Generalize README to the use case of using an already-defined proto

Vizerai/grpc,ncteisen/grpc,ctiller/grpc,thunderboltsid/grpc,Crevil/grpc,greasypizza/grpc,chai2010/grpc-common,ipylypiv/grpc,zeliard/grpc-common,grpc/grpc,firebase/grpc,muxi/grpc,arkmaxim/grpc,nicolasnoble/grpc,soltanmm-google/grpc,jtattermusch/grpc,stanley-cheung/grpc,larsonmpdx/grpc,w4-sjcho/grpc,baylabs/grpc,zhimingxie/grpc,dklempner/grpc,MakMukhi/grpc,vjpai/grpc,jboeuf/grpc-common,soltanmm/grpc-common,muxi/grpc,thinkerou/grpc,bogdandrutu/grpc,ofrobots/grpc,makdharma/grpc,adelez/grpc,jtattermusch/grpc,muxi/grpc,kpayson64/grpc,firebase/grpc,rosmo/grpc-common,leifurhauks/grpc,LuminateWireless/grpc,a11r/grpc,firebase/grpc,doubi-workshop/grpc,infinit/grpc,w4-sjcho/grpc,grani/grpc,vsco/grpc,ejona86/grpc,bogdandrutu/grpc,msmania/grpc,cgvarela/grpc,cgvarela/grpc,simonkuang/grpc,yang-g/grpc,maxwell-demon/grpc,madongfly/grpc,muxi/grpc,dgquintas/grpc,jboeuf/grpc-common,kriswuollett/grpc,nicolasnoble/grpc,tamihiro/grpc,apolcyn/grpc,vsco/grpc,wcevans/grpc,firebase/grpc,bjori/grpc,ejona86/grpc,ipylypiv/grpc,yinsu/grpc,daniel-j-born/grpc,yang-g/grpc-common,pmarks-net/grpc,jboeuf/grpc-common,mehrdada/grpc,yang-g/grpc,jcanizales/grpc,ctiller/grpc,fuchsia-mirror/third_party-grpc,matt-kwong/grpc,murgatroid99/grpc,yongni/grpc,makdharma/grpc,jboeuf/grpc-common,chrisdunelm/grpc,ncteisen/grpc,msiedlarek/grpc,msmania/grpc,kriswuollett/grpc,quizlet/grpc,yang-g/grpc,bogdandrutu/grpc,VcamX/grpc,wangyikai/grpc,kumaralokgithub/grpc,kpayson64/grpc,fuchsia-mirror/third_party-grpc,tengyifei/grpc,andrewpollock/grpc,yinsu/grpc,firebase/grpc,chrisdunelm/grpc,pmarks-net/grpc,vjpai/grpc,quizlet/grpc,jcanizales/grpc,doubi-workshop/grpc,kumaralokgithub/grpc,ctiller/grpc,deepaklukose/grpc,rosmo/grpc-common,ofrobots/grpc,apolcyn/grpc,madongfly/grpc,yinsu/grpc,soltanmm/grpc,yugui/grpc,stanley-cheung/grpc,goldenbull/grpc,quizlet/grpc,geekan/grpc-common,carl-mastrangelo/grpc,MakMukhi/grpc,firebase/grpc,malexzx/grpc,jcanizales/grpc,chai2010/grpc-common,soltanmm/grpc,geekan/grpc-common,a11r/grpc,yoshi10321/grpc-common,miselin/grpc,greasypizza/grpc,infinit/grpc,yang-g/grpc-common,msmania/grpc,leifurhauks/grpc,tamihiro/grpc,carl-mastrangelo/grpc,goldenbull/grpc,murgatroid99/grpc,LuminateWireless/grpc,tamihiro/grpc,miselin/grpc,Vizerai/grpc,geffzhang/grpc,7anner/grpc,wangyikai/grpc,carl-mastrangelo/grpc,yongni/grpc,yang-g/grpc-common,yinsu/grpc,larsonmpdx/grpc,maxwell-demon/grpc,ctiller/grpc,doubi-workshop/grpc,royalharsh/grpc,y-zeng/grpc,podsvirov/grpc,yang-g/grpc,PeterFaiman/ruby-grpc-minimal,yongni/grpc,andrewpollock/grpc,stanley-cheung/grpc,yugui/grpc,ncteisen/grpc,chrisdunelm/grpc,royalharsh/grpc,jtattermusch/grpc,yoshi10321/grpc-common,pmarks-net/grpc,ofrobots/grpc,chai2010/grpc-common,murgatroid99/grpc,zeliard/grpc-common,cgvarela/grpc,andrewpollock/grpc,arkmaxim/grpc,stanley-cheung/grpc,7anner/grpc,a11r/grpc,mehrdada/grpc,ananthonline/grpc,soltanmm/grpc-common,MakMukhi/grpc,ofrobots/grpc,deepaklukose/grpc,kumaralokgithub/grpc,perumaalgoog/grpc,PeterFaiman/ruby-grpc-minimal,kskalski/grpc,wcevans/grpc,murgatroid99/grpc,PeterFaiman/ruby-grpc-minimal,chai2010/grpc-common,jboeuf/grpc,geffzhang/grpc,podsvirov/grpc,ctiller/grpc,wcevans/grpc,bogdandrutu/grpc,muxi/grpc,a11r/grpc,pszemus/grpc,donnadionne/grpc,Vizerai/grpc,grani/grpc,a-veitch/grpc,muxi/grpc,dgquintas/grpc,vsco/grpc,Crevil/grpc,madongfly/grpc,podsvirov/grpc,donnadionne/grpc,perumaalgoog/grpc,nicolasnoble/grpc,rjshade/grpc,ananthonline/grpc,y-zeng/grpc,ofrobots/grpc,ipylypiv/grpc,kumaralokgithub/grpc,rjshade/grpc,murgatroid99/grpc,zhimingxie/grpc,tamihiro/grpc,deepaklukose/grpc,yongni/grpc,msiedlarek/grpc,MakMukhi/grpc,simonkuang/grpc,y-zeng/grpc,msmania/grpc,pszemus/grpc,ppietrasa/grpc,soltanmm-google/grpc,ctiller/grpc,kskalski/grpc,arkmaxim/grpc,tamihiro/grpc,rjshade/grpc,deepaklukose/grpc,VcamX/grpc,sreecha/grpc,miselin/grpc,royalharsh/grpc,rjshade/grpc,daniel-j-born/grpc,y-zeng/grpc,cgvarela/grpc,stanley-cheung/grpc,sreecha/grpc,yang-g/grpc-common,thunderboltsid/grpc,w4-sjcho/grpc,baylabs/grpc,soltanmm/grpc-common,leifurhauks/grpc,doubi-workshop/grpc,nicolasnoble/grpc,malexzx/grpc,andrewpollock/grpc,wcevans/grpc,tamihiro/grpc,ncteisen/grpc,kumaralokgithub/grpc,deepaklukose/grpc,andrewpollock/grpc,rosmo/grpc-common,pmarks-net/grpc,malexzx/grpc,doubi-workshop/grpc,goldenbull/grpc,stanley-cheung/grpc,jtattermusch/grpc,vjpai/grpc,pszemus/grpc,VcamX/grpc,firebase/grpc,wangyikai/grpc,ipylypiv/grpc,malexzx/grpc,thinkerou/grpc,soltanmm-google/grpc,philcleveland/grpc,wcevans/grpc,s4uliu5/grpc-common,deepaklukose/grpc,thinkerou/grpc,sreecha/grpc,soltanmm/grpc-common,zhimingxie/grpc,bogdandrutu/grpc,PeterFaiman/ruby-grpc-minimal,geffzhang/grpc,quizlet/grpc,rosmo/grpc-common,adelez/grpc,ppietrasa/grpc,wangyikai/grpc,JoeWoo/grpc,rosmo/grpc-common,stanley-cheung/grpc,mehrdada/grpc,maxwell-demon/grpc,thinkerou/grpc,arkmaxim/grpc,MakMukhi/grpc,baylabs/grpc,podsvirov/grpc,chrisdunelm/grpc,matt-kwong/grpc,thunderboltsid/grpc,ananthonline/grpc,thinkerou/grpc,a11r/grpc,s4uliu5/grpc-common,w4-sjcho/grpc,kriswuollett/grpc,deepaklukose/grpc,malexzx/grpc,dklempner/grpc,a-veitch/grpc,mehrdada/grpc,kskalski/grpc,kskalski/grpc,pszemus/grpc,geffzhang/grpc,perumaalgoog/grpc,VcamX/grpc,matt-kwong/grpc,ppietrasa/grpc,goldenbull/grpc,ejona86/grpc,tamihiro/grpc,baylabs/grpc,thunderboltsid/grpc,soltanmm/grpc-common,doubi-workshop/grpc,a-veitch/grpc,fuchsia-mirror/third_party-grpc,wangyikai/grpc,perumaalgoog/grpc,donnadionne/grpc,vjpai/grpc,philcleveland/grpc,vsco/grpc,pszemus/grpc,soltanmm/grpc,soltanmm/grpc,matt-kwong/grpc,leifurhauks/grpc,donnadionne/grpc,yang-g/grpc-common,infinit/grpc,7anner/grpc,tengyifei/grpc,w4-sjcho/grpc,thinkerou/grpc,perumaalgoog/grpc,firebase/grpc,y-zeng/grpc,andrewpollock/grpc,bjori/grpc,donnadionne/grpc,grpc/grpc,geekan/grpc-common,ppietrasa/grpc,malexzx/grpc,kpayson64/grpc,thunderboltsid/grpc,simonkuang/grpc,yongni/grpc,matt-kwong/grpc,muxi/grpc,grani/grpc,infinit/grpc,Vizerai/grpc,a-veitch/grpc,kumaralokgithub/grpc,zhimingxie/grpc,apolcyn/grpc,royalharsh/grpc,Vizerai/grpc,chai2010/grpc-common,thinkerou/grpc,yoshi10321/grpc-common,vjpai/grpc,kskalski/grpc,ppietrasa/grpc,greasypizza/grpc,thunderboltsid/grpc,MakMukhi/grpc,rjshade/grpc,greasypizza/grpc,fuchsia-mirror/third_party-grpc,maxwell-demon/grpc,pszemus/grpc,y-zeng/grpc,madongfly/grpc,geekan/grpc-common,miselin/grpc,grpc/grpc,leifurhauks/grpc,kskalski/grpc,baylabs/grpc,arkmaxim/grpc,tengyifei/grpc,s4uliu5/grpc-common,soltanmm/grpc-common,grani/grpc,jtattermusch/grpc,sreecha/grpc,zeliard/grpc-common,ejona86/grpc,s4uliu5/grpc-common,bjori/grpc,goldenbull/grpc,stanley-cheung/grpc,soltanmm/grpc,vjpai/grpc,apolcyn/grpc,chrisdunelm/grpc,ananthonline/grpc,bjori/grpc,soltanmm/grpc-common,jboeuf/grpc,daniel-j-born/grpc,LuminateWireless/grpc,chrisdunelm/grpc,firebase/grpc,LuminateWireless/grpc,ejona86/grpc,daniel-j-born/grpc,doubi-workshop/grpc,carl-mastrangelo/grpc,y-zeng/grpc,podsvirov/grpc,makdharma/grpc,grpc/grpc,kpayson64/grpc,madongfly/grpc,jcanizales/grpc,philcleveland/grpc,infinit/grpc,jtattermusch/grpc,zhimingxie/grpc,murgatroid99/grpc,daniel-j-born/grpc,stanley-cheung/grpc,carl-mastrangelo/grpc,yugui/grpc,apolcyn/grpc,VcamX/grpc,yongni/grpc,leifurhauks/grpc,yugui/grpc,grpc/grpc,yugui/grpc,geekan/grpc-common,geekan/grpc-common,Vizerai/grpc,yoshi10321/grpc-common,ananthonline/grpc,tengyifei/grpc,pszemus/grpc,ananthonline/grpc,soltanmm/grpc-common,vsco/grpc,7anner/grpc,bogdandrutu/grpc,kskalski/grpc,Crevil/grpc,vsco/grpc,wcevans/grpc,jboeuf/grpc-common,soltanmm/grpc,jtattermusch/grpc,dgquintas/grpc,yongni/grpc,yang-g/grpc,dklempner/grpc,mehrdada/grpc,JoeWoo/grpc,zeliard/grpc-common,ncteisen/grpc,hstefan/grpc,Crevil/grpc,makdharma/grpc,chrisdunelm/grpc,a11r/grpc,rjshade/grpc,jboeuf/grpc-common,VcamX/grpc,simonkuang/grpc,Crevil/grpc,adelez/grpc,dgquintas/grpc,s4uliu5/grpc-common,rjshade/grpc,geffzhang/grpc,geekan/grpc-common,yang-g/grpc-common,jboeuf/grpc,jtattermusch/grpc,simonkuang/grpc,ctiller/grpc,makdharma/grpc,7anner/grpc,goldenbull/grpc,grpc/grpc,a11r/grpc,ctiller/grpc,msiedlarek/grpc,firebase/grpc,miselin/grpc,a-veitch/grpc,thunderboltsid/grpc,chrisdunelm/grpc,grani/grpc,yongni/grpc,ncteisen/grpc,ofrobots/grpc,chrisdunelm/grpc,JoeWoo/grpc,yang-g/grpc-common,chai2010/grpc-common,stanley-cheung/grpc,thinkerou/grpc,miselin/grpc,muxi/grpc,msmania/grpc,perumaalgoog/grpc,yoshi10321/grpc-common,msiedlarek/grpc,tengyifei/grpc,ncteisen/grpc,cgvarela/grpc,rosmo/grpc-common,ppietrasa/grpc,baylabs/grpc,matt-kwong/grpc,ipylypiv/grpc,MakMukhi/grpc,maxwell-demon/grpc,leifurhauks/grpc,soltanmm-google/grpc,royalharsh/grpc,perumaalgoog/grpc,Vizerai/grpc,ncteisen/grpc,yinsu/grpc,dklempner/grpc,firebase/grpc,carl-mastrangelo/grpc,donnadionne/grpc,tengyifei/grpc,soltanmm-google/grpc,infinit/grpc,carl-mastrangelo/grpc,JoeWoo/grpc,msiedlarek/grpc,msiedlarek/grpc,yoshi10321/grpc-common,dgquintas/grpc,a11r/grpc,adelez/grpc,donnadionne/grpc,LuminateWireless/grpc,maxwell-demon/grpc,tengyifei/grpc,chai2010/grpc-common,a11r/grpc,yang-g/grpc-common,MakMukhi/grpc,yoshi10321/grpc-common,w4-sjcho/grpc,vjpai/grpc,doubi-workshop/grpc,PeterFaiman/ruby-grpc-minimal,larsonmpdx/grpc,philcleveland/grpc,grani/grpc,nicolasnoble/grpc,thinkerou/grpc,yang-g/grpc-common,msiedlarek/grpc,dklempner/grpc,kskalski/grpc,matt-kwong/grpc,vjpai/grpc,jboeuf/grpc,vjpai/grpc,podsvirov/grpc,chrisdunelm/grpc,Vizerai/grpc,philcleveland/grpc,dgquintas/grpc,ejona86/grpc,deepaklukose/grpc,bjori/grpc,LuminateWireless/grpc,grpc/grpc,fuchsia-mirror/third_party-grpc,pszemus/grpc,maxwell-demon/grpc,tamihiro/grpc,jboeuf/grpc,pmarks-net/grpc,mehrdada/grpc,jboeuf/grpc,ppietrasa/grpc,vsco/grpc,ananthonline/grpc,philcleveland/grpc,carl-mastrangelo/grpc,malexzx/grpc,JoeWoo/grpc,Vizerai/grpc,zhimingxie/grpc,rjshade/grpc,grpc/grpc,Crevil/grpc,apolcyn/grpc,zhimingxie/grpc,7anner/grpc,royalharsh/grpc,thunderboltsid/grpc,yinsu/grpc,donnadionne/grpc,goldenbull/grpc,soltanmm-google/grpc,fuchsia-mirror/third_party-grpc,ananthonline/grpc,larsonmpdx/grpc,hstefan/grpc,ananthonline/grpc,kpayson64/grpc,a-veitch/grpc,kriswuollett/grpc,ejona86/grpc,goldenbull/grpc,yoshi10321/grpc-common,zhimingxie/grpc,sreecha/grpc,soltanmm-google/grpc,miselin/grpc,muxi/grpc,quizlet/grpc,bjori/grpc,bogdandrutu/grpc,adelez/grpc,quizlet/grpc,soltanmm/grpc-common,greasypizza/grpc,w4-sjcho/grpc,ipylypiv/grpc,vjpai/grpc,nicolasnoble/grpc,fuchsia-mirror/third_party-grpc,madongfly/grpc,rosmo/grpc-common,sreecha/grpc,wangyikai/grpc,7anner/grpc,a-veitch/grpc,podsvirov/grpc,simonkuang/grpc,maxwell-demon/grpc,baylabs/grpc,ipylypiv/grpc,LuminateWireless/grpc,daniel-j-born/grpc,kpayson64/grpc,jtattermusch/grpc,simonkuang/grpc,ofrobots/grpc,larsonmpdx/grpc,jtattermusch/grpc,thinkerou/grpc,baylabs/grpc,kumaralokgithub/grpc,yang-g/grpc,fuchsia-mirror/third_party-grpc,yugui/grpc,apolcyn/grpc,msiedlarek/grpc,LuminateWireless/grpc,mehrdada/grpc,bogdandrutu/grpc,ctiller/grpc,rosmo/grpc-common,kriswuollett/grpc,ipylypiv/grpc,msmania/grpc,bjori/grpc,sreecha/grpc,geffzhang/grpc,kskalski/grpc,grani/grpc,larsonmpdx/grpc,msmania/grpc,jboeuf/grpc-common,philcleveland/grpc,ppietrasa/grpc,msmania/grpc,dklempner/grpc,PeterFaiman/ruby-grpc-minimal,nicolasnoble/grpc,jboeuf/grpc,goldenbull/grpc,muxi/grpc,ncteisen/grpc,apolcyn/grpc,adelez/grpc,yang-g/grpc,zeliard/grpc-common,jcanizales/grpc,geffzhang/grpc,malexzx/grpc,donnadionne/grpc,wangyikai/grpc,baylabs/grpc,dklempner/grpc,sreecha/grpc,hstefan/grpc,stanley-cheung/grpc,greasypizza/grpc,mehrdada/grpc,zeliard/grpc-common,simonkuang/grpc,vsco/grpc,PeterFaiman/ruby-grpc-minimal,sreecha/grpc,MakMukhi/grpc,yinsu/grpc,bjori/grpc,madongfly/grpc,kumaralokgithub/grpc,murgatroid99/grpc,mehrdada/grpc,wcevans/grpc,andrewpollock/grpc,kpayson64/grpc,greasypizza/grpc,yoshi10321/grpc-common,makdharma/grpc,ppietrasa/grpc,ejona86/grpc,arkmaxim/grpc,kriswuollett/grpc,stanley-cheung/grpc,pmarks-net/grpc,Crevil/grpc,quizlet/grpc,yang-g/grpc,pmarks-net/grpc,tengyifei/grpc,malexzx/grpc,nicolasnoble/grpc,geffzhang/grpc,LuminateWireless/grpc,jboeuf/grpc,simonkuang/grpc,chai2010/grpc-common,rosmo/grpc-common,madongfly/grpc,soltanmm-google/grpc,jboeuf/grpc-common,jtattermusch/grpc,deepaklukose/grpc,matt-kwong/grpc,matt-kwong/grpc,zeliard/grpc-common,geekan/grpc-common,s4uliu5/grpc-common,chai2010/grpc-common,wangyikai/grpc,yugui/grpc,royalharsh/grpc,andrewpollock/grpc,grpc/grpc,grani/grpc,fuchsia-mirror/third_party-grpc,leifurhauks/grpc,quizlet/grpc,soltanmm-google/grpc,tengyifei/grpc,philcleveland/grpc,yang-g/grpc,donnadionne/grpc,cgvarela/grpc,zeliard/grpc-common,mehrdada/grpc,quizlet/grpc,jboeuf/grpc-common,thinkerou/grpc,larsonmpdx/grpc,w4-sjcho/grpc,jboeuf/grpc,wangyikai/grpc,jtattermusch/grpc,chrisdunelm/grpc,rjshade/grpc,JoeWoo/grpc,grpc/grpc,bjori/grpc,murgatroid99/grpc,PeterFaiman/ruby-grpc-minimal,muxi/grpc,infinit/grpc,a-veitch/grpc,maxwell-demon/grpc,hstefan/grpc,jcanizales/grpc,royalharsh/grpc,PeterFaiman/ruby-grpc-minimal,hstefan/grpc,madongfly/grpc,donnadionne/grpc,perumaalgoog/grpc,hstefan/grpc,zeliard/grpc-common,kpayson64/grpc,VcamX/grpc,leifurhauks/grpc,dgquintas/grpc,larsonmpdx/grpc,sreecha/grpc,perumaalgoog/grpc,pszemus/grpc,hstefan/grpc,miselin/grpc,thunderboltsid/grpc,kriswuollett/grpc,ctiller/grpc,kriswuollett/grpc,pszemus/grpc,jboeuf/grpc,murgatroid99/grpc,nicolasnoble/grpc,vsco/grpc,Crevil/grpc,yugui/grpc,soltanmm/grpc,soltanmm/grpc,cgvarela/grpc,kpayson64/grpc,mehrdada/grpc,adelez/grpc,s4uliu5/grpc-common,kriswuollett/grpc,wcevans/grpc,nicolasnoble/grpc,jcanizales/grpc,ncteisen/grpc,jboeuf/grpc,ncteisen/grpc,geffzhang/grpc,murgatroid99/grpc,royalharsh/grpc,carl-mastrangelo/grpc,podsvirov/grpc,dklempner/grpc,vjpai/grpc,JoeWoo/grpc,ipylypiv/grpc,msiedlarek/grpc,daniel-j-born/grpc,jcanizales/grpc,miselin/grpc,y-zeng/grpc,yinsu/grpc,ofrobots/grpc,nicolasnoble/grpc,dgquintas/grpc,makdharma/grpc,yugui/grpc,7anner/grpc,ctiller/grpc,mehrdada/grpc,makdharma/grpc,ejona86/grpc,s4uliu5/grpc-common,dgquintas/grpc,infinit/grpc,arkmaxim/grpc,carl-mastrangelo/grpc,adelez/grpc,pmarks-net/grpc,ejona86/grpc,PeterFaiman/ruby-grpc-minimal,wcevans/grpc,ofrobots/grpc,infinit/grpc,vjpai/grpc,sreecha/grpc,kpayson64/grpc,kpayson64/grpc,makdharma/grpc,cgvarela/grpc,muxi/grpc,geekan/grpc-common,philcleveland/grpc,apolcyn/grpc,nicolasnoble/grpc,firebase/grpc,sreecha/grpc,larsonmpdx/grpc,dklempner/grpc,Vizerai/grpc,ejona86/grpc,jboeuf/grpc,carl-mastrangelo/grpc,doubi-workshop/grpc,andrewpollock/grpc,bogdandrutu/grpc,daniel-j-born/grpc,JoeWoo/grpc,s4uliu5/grpc-common,dgquintas/grpc,grpc/grpc,adelez/grpc,y-zeng/grpc,yinsu/grpc,tamihiro/grpc,zhimingxie/grpc,arkmaxim/grpc,pszemus/grpc,ejona86/grpc,pmarks-net/grpc,Crevil/grpc,hstefan/grpc,podsvirov/grpc,greasypizza/grpc,ctiller/grpc,VcamX/grpc,daniel-j-born/grpc,JoeWoo/grpc,grpc/grpc,kumaralokgithub/grpc,jcanizales/grpc,ncteisen/grpc,VcamX/grpc,greasypizza/grpc,a-veitch/grpc,grani/grpc,hstefan/grpc,donnadionne/grpc,yongni/grpc,msmania/grpc,arkmaxim/grpc,thinkerou/grpc,fuchsia-mirror/third_party-grpc,Vizerai/grpc,w4-sjcho/grpc,carl-mastrangelo/grpc,dgquintas/grpc,soltanmm/grpc,7anner/grpc,pszemus/grpc