Continuously deliver package releases and publication #8

A change to the main branch triggers a release and publication workflow; manual approval is required to actually create the release and publish the package

1. A change is pushed to the main branch.
2. A workflow conducts all release/publications steps up to and therefore excluding the actual creation of the release, release tag, publication, etc. artifacts. This ensures that the package can be released/published before attempting the actual release/publication.
3. A manual approval gate exists that requires manual approval by at least one user from a specified subset of users (including the project owner).
4. Once approved, the package is released and published so that:

• Release notes are generated.
• A new release is published to the GitHub project, which includes the release notes.
• The package is published to PyPi.

Releases shall follow semantic versioning. The version to increment shall be identified at an appropriate point in the release workflow.