removed old `app.error()` docs
removed old `app.error()` docs

jinghuizhai/express,hightechweb/express,pshomov/express,Matrixbirds/express,Riokai/express,junxiong/express,stewartml/express,angelsanz/express,WangCao/express,nodejs-camp/booklog-chle,microlv/express,flomotlik/express,dongooo/express,nodejs-camp/booklog-tonebeta-update,1verson/express,dieuly/express,blairzhang/express,jymsy/express,hanqingnan/express,RanadeepPolavarapu/express,chrisinajar/express,r14r/fork_express_master,stevemao/express,srichatala/express,dongseop/express,sibura/express,fineday32/express,christopheranderson/express,pshomov/express,robomc/express,supasate/express,nodejs-camp/booklog-jollen,za-creature/express,nodejs-camp/booklog-ausir,corporateanon/express,xiaofuzi/express,gdeividas/express,drzorm/express,awronka/express,shanawarkhan/express,shanawarkhan/express,WangCao/express,methuz/express,vinodhalaharvi/express,elkingtonmcb/express,maraoz/express,lian774739140/express,dongooo/express,leiqiang75/express,stewartml/express,Jonekee/express,chuym/express,thepont/express,lemelon/express,robomc/express,mcanthony/express,Flip120/express,caiocutrim/express,yinhe007/express,michaeljunlove/express,evilboss/express,nodejs-camp/booklog-ben,awronka/express,bercanozcan/express,micha149/express,samuelcastro/express,XueQian/express,nodejs-camp/booklog-s890506,nodejs-camp/booklog-ausir,bjrmatos/express,saisai/express,leiqiang75/express,KodkodGates/express,bjrmatos/express,Talkyunyun/express,FernAbby/express,drzorm/express,xiaofuzi/express,sarvex/express,dongseop/express,rgrove/express,qq645381995/express,jenalgit/express,topaxi/express,igarciaes/express,nodejs-camp/booklog-polo,ericlu88/express,gnowoel/express,jimmykuo/express,stewartml/express,KodkodGates/express,vnglst/express,dafabulousteach/express,Ju2ender/express,Faiz7412/express,ZackBotkin/express,Talkyunyun/express,juandav/express,Matrixbirds/express,v10258/express,wesleytodd/express,Jonekee/express,abhi3/express,tianhengzhou/express,dongseop/express,emvici/emvici-reqres-tify,dafabulousteach/express,devgeniem/express,nodejs-camp/booklog-ansaga,andriyl/express,youprofit/express,wtony/express,xtidt/express,gnowoel/express,nodejs-camp/booklog-linkchen,pstrike/express,kentcdodds/express,codeforgeek/express,hdngr/express,sujianping/express,chrisinajar/express,hacksparrow/express,stevemao/express,Haru1990/express,jinghuizhai/express,angelsanz/express,simudream/express,juanpastas/express,kunalpict/express,stoskov/express,xiaofuzi/express,vnglst/express,1verson/express,demohi/express,blainsmith/express,sujianping/express,nodejs-camp/booklog-jason,nodejs-camp/booklog-homa,coreypnorris/express,microlv/express,gdeividas/express,soyuka/express,Faiz7412/express,nbeydoon/express,stevemao/express,smcmurray/express,nodejs-camp/booklog-jason,nodejs-camp/booklog-tonebeta-update,gretac/express,Ju2ender/express,elkingtonmcb/express,corporateanon/express,RanadeepPolavarapu/express,tjmehta/express,lmtdit/express,jinghuizhai/express,danielrohers/express,devgeniem/express,grigorkh/express,kylezhang/express,BaggersIO/express,fuse-mars/express,Faiz7412/express,nodejs-camp/booklog-chenyou,fuse-mars/express,ahdinosaur/express,Riokai/express,fanzetao/express,hightechweb/express,dotnetCarpenter/express,topaxi/express,smcmurray/express,featurist/express,coreypnorris/express,kunalpict/express,featurist/express,vnglst/express,mikewesthad/express,grigorkh/express,WebStyle/express,kubrickology/express,coreypnorris/express,BaggersIO/express,swstack/express,featurist/express,jymsy/express,XueQian/express,Flip120/express,fakedarren/express,methuz/express,nodejs-camp/booklog-Zak,michaeljunlove/express,JulyZhu/express,r14r-work/fork_express_master,jenia0jenia/express,btleffler/express,Haru1990/express,dreamingblackcat/express,nodejs-camp/booklog-tonebeta,wtony/express,vidyar/express,adjohnson916/express,CrazySherman/express,vidyar/express,codeforgeek/express,maraoz/express,swstack/express,lmtdit/express,sarvex/express,nodejs-camp/booklog-leo,Eric-Vandenberg/express,benshiue/booklog-ben,smcmurray/express,rupanjanbaidya/express,supasate/express,listepo/express,yinhe007/express,aifeld/express,VegeChou/express,ifraixedes/express,angelsanz/express,supasate/express,youprofit/express,baldurh/express,llwanghong/express,FernAbby/express,hanqingnan/express,cflynn07/express,qitianchan/express,LestaD/express,simudream/express,hdngr/express,pathirana/express,BaggersIO/express,neomadara/express,demohi/express,corporateanon/express,dgofman/express,qq645381995/express,andriyl/express,xtidt/express,bercanozcan/express,pstrike/express,jenalgit/express,wesleytodd/express,brianloveswords/express,MoraLin/mora-test,Kevnz/express,philxia/ex-tst-framework,hanweifish/express,heicx/express,hanweifish/express,blairzhang/express,nodejs-camp/booklog-leo,countdracular/express,vinodhalaharvi/express,WangCao/express,nathan818fr/express,nodejs-camp/booklog-jollen,dreamingblackcat/express,nodejs-camp/booklog-Zak,RickyDan/express,evanlucas/express,flomotlik/express,kylezhang/express,christopheranderson/express,chuym/express,neomadara/express,strongloop/express,ralic/express,za-creature/express,dieuly/express,cflynn07/express,countdracular/express,nodejs-camp/booklog-homa,stoskov/express,WebStyle/express,YR/express,hpcslag/express,lmtdit/express,frootloops/express,junxiong/express,hpcslag/express,nbeydoon/express,andrejewski/express,auth0/express,udhayam/express,isaacs/express,friederbluemle/express,danielrohers/express,CrazySherman/express,nodejs-camp/booklog-chenyou,tjmehta/express,swarajgiri/express,ci-test2/express,nathan818fr/express,gnowoel/express,andrejewski/express,za-creature/express,mikewesthad/express,auth0/express,MoraLin/mora-test,Kevnz/express,PeterWangPo/express,mauricionr/express,michaeljunlove/express,rgrove/express,PUSEN/express,juandav/express,blakeembrey/express,qitianchan/express,abdulhannanali/express,ci-test2/express,caiocutrim/express,sibura/express,lemelon/express,qitianchan/express,adjohnson916/express,Ju2ender/express,expressjs/express,fakedarren/express,svnh/express,jenia0jenia/express,Eric-Vandenberg/express,RickyDan/express,samuelcastro/express,mimaidms/express,Eric-Vandenberg/express,simudream/express,llwanghong/express,v10258/express,dsupera13/express,kubrickology/express,kylezhang/express,buildsample/express,luxe-eng/valet-express.express,LestaD/express,soyuka/express,tyler-johnson/express,swarajgiri/express,dafabulousteach/express,tianhengzhou/express,ci-test2/express,chrisinajar/express,wtony/express,pathirana/express,Riokai/express,lian774739140/express,luxe-eng/valet-express.express,nodejs-camp/booklog-archer,youprofit/express,svnh/express,kentcdodds/express,igarciaes/express,philxia/ex-tst-framework,jenia0jenia/express,hacksparrow/express,grigorkh/express,ericlu88/express,listepo/express,vidyar/express,TestingCI/express,PeterWangPo/express,expressjs/express,aifeld/express,weilixia/express,luxe-eng/valet-express.express,dsupera13/express,blairzhang/express,svnh/express,dgofman/express,KodkodGates/express,dotnetCarpenter/express,hdngr/express,weilixia/express,abhi3/express,strongloop/express,1amageek/express,sarvex/express,nodejs-camp/booklog-mora,nbeydoon/express,Lexine/express,nodejs-camp/booklog-s890506,LestaD/express,swarajgiri/express,listepo/express,1amageek/express,TestingCI/express,heicx/express,kawanet/express,ahdinosaur/express,JulyZhu/express,junxiong/express,PUSEN/express,btleffler/express,fakedarren/express,fanzetao/express,philxia/ex-tst-framework,Ivanwangcy/express,topaxi/express,mimaidms/express,tyler-johnson/express,evanlucas/express,r14r/fork_express_master,qq645381995/express,simplyianm/express,baldurh/express,nodejs-camp/booklog-chle,juanpastas/express,buildsample/express,stoskov/express,blakeembrey/express,nodejs-camp/booklog-polo,blakeembrey/express,frootloops/express,1amageek/express,nodejs-camp/booklog-mora,ZackBotkin/express,friederbluemle/express,nodejs-camp/booklog-linkchen,saisai/express,nodejs-camp/booklog-polo,Lexine/express,blainsmith/express,nodejs-camp/booklog-ansaga,friederbluemle/express,HXYNODE/express,devgeniem/express,v10258/express,vinodhalaharvi/express,bercanozcan/express,dreamingblackcat/express,evilboss/express,dotnetCarpenter/express,benshiue/booklog-ben,jimmykuo/express,mcanthony/express,nodejs-camp/booklog-archer,ralic/express,hl198181/express,YR/express,philxia/ex-tst-framework,thepont/express,ZackBotkin/express,udhayam/express,evilboss/express,isaacs/express,abdulhannanali/express,Flip120/express,abdulhannanali/express,jenalgit/express,r14r-work/fork_express_master,simplyianm/express,nodejs-camp/booklog-ben,TestingCI/express,micha149/express,gretac/express,maraoz/express,nodejs-camp/booklog-tonebeta,VegeChou/express,fineday32/express,hpcslag/express,XueQian/express,kawanet/express,srichatala/express,buildsample/express,Ivanwangcy/express,abhi3/express,mauricionr/express,kunalpict/express,ifraixedes/express,rupanjanbaidya/express,hl198181/express,HXYNODE/express