Release notes should be something else than the README

[chaen]

When doing a github release (i.e. commit to master), the release notes are just the README.md. We should have something sensible (PR description/commit message/else)

[aldbr]

ddev:

• [ ] instead of using the readme, extract the commit message to create the release (reference the DiracX/DiracX-Web commits that might have triggered the release)

No need to adjust the previous releases.