Docs: need a page explaining Akka.Persistence tagging

[Aaronontheweb]

Please describe what you are trying to understand

Somehow, we don't have an easily discoverable page that explains how to work with Akka.Persistence tagging anywhere.

Which pages have you looked at?

1. Event adapters - https://getakka.net/articles/persistence/event-adapters.html
2. Persistence.Query - https://getakka.net/articles/persistence/persistence-query.html#eventsbytag-and-currenteventsbytag - kind of mentions it, but it's a very round-about way of doing it