docs: warn against using `rebaseWhen=never` plus `prCreation=not-pending` (#13223)

docs/usage/configuration-options.md

@@ -1998,6 +1998,8 @@ Possible values and meanings:
 
 It is also recommended to avoid `rebaseWhen=never` as it can result in conflicted branches with outdated PR descriptions and/or status checks.
 
+Avoid setting `rebaseWhen=never` and then also setting `prCreation=not-pending` as this can prevent creation of PRs.
+
 ## recreateClosed
 
 By default, Renovate will detect if it has proposed an update to a project before and not propose the same one again.