[DOCS] Improve DistributedPubSub XML-DOC#7718

Aaronontheweb merged 1 commit intoakkadotnet:devakkadotnet/akka.net:devfrom

Arkatufus:docs/PubSub-add-XMLDOCArkatufus/akka.net:docs/PubSub-add-XMLDOCCopy head branch name to clipboard