Publish workflow 2.0

[theschitz]

Continuation of #338

We now have a first version of a release workflow (hopefully) in action. There are however some small bits left to make the process complete and (maybe) allow for a fully automated delivery workflow one day.

• Update changelog on release
  • Hopefully our use of conventional commits have matured enough to enable some kind of automated generation of the changelog.
    • It's not unlikely that edits might be necessary. How to solve this?
    • There might be some issues with the way we version for release and pre-release.
• Trigger release on a release branch (and pre-release?)
  • When a push is made to the release branch, the release workflow starts.
  • In the end of the workflow, if all succeeds:
    • A Pull Request is created against the master branch
    • The PR is automatically completed and merged, removing release branch
  • We should first investigate if there exists any GitHub action that already supports this approach