Git workflow: add dev branch and manage release creation

[racousin]

• add add_action_for_dev_branch
• add release process (md file and workflow)

[14renus]

Copying @racousin's comment from closed PR (#45) to keep track:

main should remain stable and production-ready at all times. Only thoroughly tested and reviewed code gets merged into main, typically during a release.

dev will be our integration branch, where ongoing work from multiple feature or bugfix branches gets merged. It’s where we do most of the development and testing.

Feature branches (e.g. dev/feature-name, fix/bug-name) branch off from dev, not main.

Once the work in dev is ready for release, we merge it into main and tag the release (e.g. v0.1.0).