chore: use git-cliff for automatic changelog generation

[JKRhb]

Thanks to @jwhb, I discovered git-cliff which is a very neat changelog generator :) This PR introduces a configuration file for git-cliff to the project and applies the tool to the project in order to regenerate the CHANGELOG.md automatically.

In the context of #118, it might also be possible to integrate the changelog generation into the release process, but more on that later.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 65.79%. Comparing base (a751ed8) to head (25a04f0).
Report is 10 commits behind head on main.

❗ Current head 25a04f0 differs from pull request most recent head 6d7e974

Please upload reports for the commit 6d7e974 to get more accurate results.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #120   +/-   ##
=======================================
  Coverage   65.79%   65.79%           
=======================================
  Files          74       74           
  Lines        2383     2383           
=======================================
  Hits         1568     1568           
  Misses        815      815           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[JKRhb]

I think the config and the new changelog format are now ready to be merged :) In a follow-up PR, I will add some additional documentation on how the new (sadly still somewhat manual) workflow will work alongside the addition of a CONTRIBUTING.md file.