!str #16455 Remove unused fanout settings
!str #16557 Rename Source.singleton to Source.single
=str #16479 Make constructor of FreeDirective internal
Merge pull request #16558 from akka/wip-16479-FreeDirective-patriknw

=str #16479 Make constructor of FreeDirective internal
Merge pull request #16556 from akka/wip-16455-cleanup-materializer-settings-patriknw

!str #16455 Remove unused fanout settings
Merge pull request #16559 from akka/wip-16557-Source.single-patriknw

!str #16557 Rename Source.singleton to Source.single
+doc akka streams docs, flowGraphs