Auto format / rename on rule PRs

Can we leverage CI to auto apply `capafmt.py` and rename files for example?

It can be cumbersome to keep track of all the necessary changes manually, see e.g. #515

refs:
- https://github.com/stefanzweifel/git-auto-commit-action
- https://michaelheap.com/git-auto-commit/
- https://driesvints.com/blog/code-style-formatting-with-github-actions
- https://peterevans.dev/posts/github-actions-how-to-automate-code-formatting-in-pull-requests/

Start by reading capafmt.py and reviewing the changes referenced in #515. Compare the linked GitHub Actions automation examples, then define how rule pull requests should run formatting and file renaming, including what committed changes indicate that the workflow is done.

Written by the indexing model from the issue text.