fix SourceQueue docs inconsistencies
fix SourceQueue docs inconsistencies

amichel/akka.net,heynickc/akka.net,amichel/akka.net,simonlaroche/akka.net,Silv3rcircl3/akka.net,ali-ince/akka.net,ali-ince/akka.net,heynickc/akka.net,simonlaroche/akka.net,Silv3rcircl3/akka.net