So that they don't overwrite the beta release notes. This means that
there's no way to update the beta release notes, but I guess that can be
done manually.
I'm going to create a new page for 'in progress' release notes, and only
write the release notes pages for actual release (including beta
releases). That way the beta release notes can be left in place while
the release notes are updated for the next beta/full release. Changes to
the release notes after the final release will be updated.
