doc: better link for embed etcd
doc: better link for embed etcd

xiang90/etcd,tguangch/etcd,glevand/coreos--etcd,akauppi/etcd,YuleiXiao/etcd,jlamillan/etcd,swingbach/etcd,ajityagaty/etcd,OyTao/etcd_learning,visheshnp/etcd,etcd-io/etcd,rnaveiras/etcd,fanminshi/etcd,lumjjb/etcd,dannysauer/etcd,bdarnell/etcd,zaphod-concur/etcd,linuxcer/etcd,nekto0n/etcd,mqliang/etcd,mkumatag/etcd,sebrandon1/etcd,hongchaodeng/etcd,whuwxl/etcd,plasticbox/etcd,yudai/etcd,xiang90/etcd,glycerine/etcd,coreos/etcd,bdarnell/etcd,OyTao/etcd_learning,jonboulle/etcd,insequent/etcd,rchicoli/etcd,luxas/etcd,insequent/etcd,li-ang/etcd,ravigadde/etcd,linuxcer/etcd,ktateish/etcd,rnaveiras/etcd,yudai/etcd,jonboulle/etcd,qqsun8819/etcd,ajityagaty/etcd,glycerine/etcd,glevand/coreos--etcd,mickep76/etcd,sebrandon1/etcd,bluebreezecf/etcd,hongchaodeng/etcd,armstrongli/etcd,bluebreezecf/etcd,jlamillan/etcd,purpleidea/etcd,lorneli/etcd,swingbach/etcd,armstrongli/etcd,purpleidea/etcd,gyuho/etcd,a-robinson/etcd,rchicoli/etcd,lumjjb/etcd,whuwxl/etcd,CrazyJvm/etcd,gyuho/etcd,cockroachdb/etcd,fanminshi/etcd,joshix/etcd,mqliang/etcd,tguangch/etcd,akauppi/etcd,heyitsanthony/etcd,visheshnp/etcd,plasticbox/etcd,dannysauer/etcd,heyitsanthony/etcd,vimalk78/etcd,CrazyJvm/etcd,YuleiXiao/etcd,sinsharat/etcd,endocode/etcd,rnaveiras/etcd,handsomesun/etcd,li-ang/etcd,coreos/etcd,zaphod-concur/etcd,handsomesun/etcd,ajityagaty/etcd,sinsharat/etcd,nekto0n/etcd,qqsun8819/etcd,etcd-io/etcd,joshix/etcd,cockroachdb/etcd,luxas/etcd,ravigadde/etcd,a-robinson/etcd,lorneli/etcd,etcd-io/etcd,mkumatag/etcd,ktateish/etcd,mickep76/etcd,vimalk78/etcd,endocode/etcd,mqliang/etcd,mkumatag/etcd