docs: describe Renovate version support in FAQ (#10073)

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>

docs/usage/faq.md

@@ -31,6 +31,14 @@ It therefore makes sense for Renovate to replace `master` with `main` where poss
 A branch name has no special meaning within the Git program, it's just a name.
 The base branch could be called `trunk` or `mainline` or `prod`, and Git would work just as well.
 
+## Which Renovate versions are officialy supported?
+
+The Renovate maintainers only support the latest version of Renovate.
+The Renovate team will only create bugfixes for an older version if the hosted app needs to stay on an older major version for a short time or if some critical bug needs to be fixed and the new major is blocked.
+
+If you're using the hosted app, you don't need to do anything, as the Renovate maintainers update the hosted app regularly.
+If you're self hosting Renovate, use the latest release if possible.
+
 ## What if I need to .. ?
 
 ### Use an alternative branch as my Pull Request target