* Implement a re-usable GitHub Action
Implement a GitHub action that can be reused across projects that want
to run black as part of their CI workflows.
* Fix typo in README.md
Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>
* Use latest Python 3
Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>