Barring exceptional circumstances, this two-liner should be the fix for this issue, i.e. operator error.
When a version record is updated, this will purge from the cache all the release notes associated with that version. We could further limit it to the latest major/minor, but I do want to anticipate any errors that could occur with setting the version record, e.g. an overincrement.
This also purges the "/docs/release/" page itself, as that needs to contain the updated list of release notes.
It should probably have a trailing slash at the version specific one, and probably a terminating dollar?
