Improve documentation of :module etc (Trac #8622)
Improve documentation of :module etc (Trac #8622)

I did quite a bit of restructuring, as well as adding
the note specifically referred to in #8622

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