Unclear that valkey is supported?

[bwitt]

It's perhaps a bit unclear that valkey is supported by this module. Neither the README nor REFERENCE.md mentions it.

Maybe we should put a note in one or the other?

Ref #573

[TheMeier]

A support claim should only be made where valkey is actually used in acceptance test though. I wanted to check that out a bit anyway

[ekohl]

We run them on EL 10 which only ships Valkey (and #559 confirms that it did so). Adding a note for that is probably a good thing.

[TheMeier]

Well D13 also ships it, and I am quite interested on getting that tested ans supported.