Add support to create pre-releases with a generated changelog

[NotTheEvilOne]

What this PR does / why we need it:
This PR enhances existing tooling to handle GitHub releases and adds support to generate a changelog for new releases of the python-gardenlinux-lib.

Which issue(s) this PR fixes:
Fixes #229
Fixes gardenlinux/gardenlinux#3800
Superseeds #210
Superseeds #230

[NotTheEvilOne]

It would be great if this PR adds a written document on how (pre-)releases are created and which steps this includes.

Added with https://github.com/gardenlinux/python-gardenlinux-lib/blob/7c408ace805de2a8559fc31be2abbb6abd4d1ae9/docs/release.rst

[yeoldegrove]

It would be great if this PR adds a written document on how (pre-)releases are created and which steps this includes.

Added with https://github.com/gardenlinux/python-gardenlinux-lib/blob/7c408ace805de2a8559fc31be2abbb6abd4d1ae9/docs/release.rst

Could we extend this a bit so that it really also talks about the actual steps to be taken?

• Bump Versions in which files and why?
  • e.g. :since: 0.7.0
  • pyproject.toml
  • .github/actions/*/*.yml
• Command to do the tagging
• How to use a new release in projects that consume the lib?

[yeoldegrove]

Thanks for the work.
I would vote for merging this and extending it in an iterative manner if needed.

[vivus-ignis]

Minor corrections/questions. Otherwise: great work!

[vivus-ignis]

LGTM!