Improve sync-all usage doc
Improve sync-all usage doc

holzensp/ghc,siddhanathan/ghc,ezyang/ghc,TomMD/ghc,lukexi/ghc-7.8-arm64,AlexanderPankiv/ghc,acowley/ghc,ml9951/ghc,elieux/ghc,olsner/ghc,GaloisInc/halvm-ghc,sgillespie/ghc,green-haskell/ghc,shlevy/ghc,gcampax/ghc,mettekou/ghc,acowley/ghc,snoyberg/ghc,forked-upstream-packages-for-ghcjs/ghc,mcschroeder/ghc,tjakway/ghcjvm,frantisekfarka/ghc-dsi,bitemyapp/ghc,gridaphobe/ghc,shlevy/ghc,mcschroeder/ghc,sdiehl/ghc,olsner/ghc,green-haskell/ghc,hferreiro/replay,elieux/ghc,gridaphobe/ghc,oldmanmike/ghc,ghc-android/ghc,spacekitteh/smcghc,urbanslug/ghc,vTurbine/ghc,lukexi/ghc-7.8-arm64,urbanslug/ghc,jstolarek/ghc,ml9951/ghc,frantisekfarka/ghc-dsi,lukexi/ghc,da-x/ghc,wxwxwwxxx/ghc,nkaretnikov/ghc,AlexanderPankiv/ghc,da-x/ghc,wxwxwwxxx/ghc,ezyang/ghc,fmthoma/ghc,mfine/ghc,gridaphobe/ghc,christiaanb/ghc,sdiehl/ghc,mcmaniac/ghc,AlexanderPankiv/ghc,frantisekfarka/ghc-dsi,forked-upstream-packages-for-ghcjs/ghc,bitemyapp/ghc,vTurbine/ghc,olsner/ghc,ezyang/ghc,vikraman/ghc,ryantm/ghc,anton-dessiatov/ghc,nathyong/microghc-ghc,TomMD/ghc,ekmett/ghc,acowley/ghc,ryantm/ghc,ezyang/ghc,lukexi/ghc-7.8-arm64,siddhanathan/ghc,siddhanathan/ghc,shlevy/ghc,mcschroeder/ghc,holzensp/ghc,ml9951/ghc,ghc-android/ghc,sdiehl/ghc,GaloisInc/halvm-ghc,mcschroeder/ghc,wxwxwwxxx/ghc,ekmett/ghc,anton-dessiatov/ghc,christiaanb/ghc,mcschroeder/ghc,ezyang/ghc,GaloisInc/halvm-ghc,fmthoma/ghc,nushio3/ghc,urbanslug/ghc,olsner/ghc,nomeata/ghc,bitemyapp/ghc,hferreiro/replay,ml9951/ghc,sgillespie/ghc,ezyang/ghc,nushio3/ghc,mfine/ghc,olsner/ghc,acowley/ghc,oldmanmike/ghc,sgillespie/ghc,ryantm/ghc,tjakway/ghcjvm,ekmett/ghc,tjakway/ghcjvm,nathyong/microghc-ghc,TomMD/ghc,AlexanderPankiv/ghc,shlevy/ghc,AlexanderPankiv/ghc,forked-upstream-packages-for-ghcjs/ghc,gridaphobe/ghc,forked-upstream-packages-for-ghcjs/ghc,olsner/ghc,nushio3/ghc,nkaretnikov/ghc,gcampax/ghc,nomeata/ghc,mcmaniac/ghc,anton-dessiatov/ghc,vikraman/ghc,elieux/ghc,forked-upstream-packages-for-ghcjs/ghc,fmthoma/ghc,wxwxwwxxx/ghc,holzensp/ghc,lukexi/ghc-7.8-arm64,urbanslug/ghc,nathyong/microghc-ghc,fmthoma/ghc,nathyong/microghc-ghc,vikraman/ghc,sdiehl/ghc,oldmanmike/ghc,oldmanmike/ghc,wxwxwwxxx/ghc,jstolarek/ghc,sdiehl/ghc,nathyong/microghc-ghc,vikraman/ghc,christiaanb/ghc,tjakway/ghcjvm,AlexanderPankiv/ghc,gcampax/ghc,GaloisInc/halvm-ghc,fmthoma/ghc,mettekou/ghc,christiaanb/ghc,GaloisInc/halvm-ghc,gcampax/ghc,vTurbine/ghc,GaloisInc/halvm-ghc,anton-dessiatov/ghc,olsner/ghc,acowley/ghc,nkaretnikov/ghc,mettekou/ghc,da-x/ghc,ml9951/ghc,gcampax/ghc,acowley/ghc,shlevy/ghc,mfine/ghc,mettekou/ghc,spacekitteh/smcghc,siddhanathan/ghc,green-haskell/ghc,nkaretnikov/ghc,GaloisInc/halvm-ghc,nkaretnikov/ghc,sdiehl/ghc,nushio3/ghc,ghc-android/ghc,snoyberg/ghc,oldmanmike/ghc,vTurbine/ghc,vikraman/ghc,elieux/ghc,shlevy/ghc,spacekitteh/smcghc,da-x/ghc,forked-upstream-packages-for-ghcjs/ghc,anton-dessiatov/ghc,fmthoma/ghc,mcschroeder/ghc,vTurbine/ghc,vTurbine/ghc,sdiehl/ghc,tjakway/ghcjvm,oldmanmike/ghc,vTurbine/ghc,ghc-android/ghc,forked-upstream-packages-for-ghcjs/ghc,anton-dessiatov/ghc,ekmett/ghc,tibbe/ghc,green-haskell/ghc,urbanslug/ghc,ryantm/ghc,snoyberg/ghc,acowley/ghc,christiaanb/ghc,elieux/ghc,ryantm/ghc,urbanslug/ghc,tjakway/ghcjvm,AlexanderPankiv/ghc,gcampax/ghc,oldmanmike/ghc,snoyberg/ghc,nomeata/ghc,ekmett/ghc,sgillespie/ghc,holzensp/ghc,hferreiro/replay,snoyberg/ghc,spacekitteh/smcghc,nomeata/ghc,wxwxwwxxx/ghc,TomMD/ghc,fmthoma/ghc,gcampax/ghc,elieux/ghc,ghc-android/ghc,gridaphobe/ghc,frantisekfarka/ghc-dsi,ml9951/ghc,tibbe/ghc,mcmaniac/ghc,siddhanathan/ghc,christiaanb/ghc,jstolarek/ghc,da-x/ghc,gridaphobe/ghc,siddhanathan/ghc,snoyberg/ghc,lukexi/ghc-7.8-arm64,nomeata/ghc,mettekou/ghc,jstolarek/ghc,nushio3/ghc,ezyang/ghc,nushio3/ghc,anton-dessiatov/ghc,nathyong/microghc-ghc,tibbe/ghc,christiaanb/ghc,lukexi/ghc,nushio3/ghc,mcschroeder/ghc,hferreiro/replay,mcmaniac/ghc,holzensp/ghc,sgillespie/ghc,bitemyapp/ghc,jstolarek/ghc,TomMD/ghc,ml9951/ghc,shlevy/ghc,mfine/ghc,ml9951/ghc,spacekitteh/smcghc,nathyong/microghc-ghc,tibbe/ghc,mfine/ghc,lukexi/ghc,hferreiro/replay,mettekou/ghc,TomMD/ghc,ghc-android/ghc,ghc-android/ghc,mcmaniac/ghc,bitemyapp/ghc,lukexi/ghc,lukexi/ghc,da-x/ghc,gridaphobe/ghc,wxwxwwxxx/ghc,vikraman/ghc,da-x/ghc,hferreiro/replay,sgillespie/ghc,mfine/ghc,nkaretnikov/ghc,elieux/ghc,siddhanathan/ghc,mettekou/ghc,tibbe/ghc,tjakway/ghcjvm,snoyberg/ghc,urbanslug/ghc,sgillespie/ghc,mfine/ghc,green-haskell/ghc,frantisekfarka/ghc-dsi,hferreiro/replay,nkaretnikov/ghc,TomMD/ghc,vikraman/ghc