Consistency between GH releases and release-notes.md

[gaeljw]

I noticed that Release Drafter is used for GH releases but a RELEASE-NOTES.md file is manually maintained.

I'm not sure yet how but it would be nice to keep both consistent.

I would also consider renaming the file to CHANGELOG.md as I know some tools (I have Renovate in mind) uses this file to pick up changelogs but not a strong requirement as I think Renovate also is able to pull changelog from GH releases.