Set up Github Actions and discuss CI/CD

Not even [Dependabot](https://docs.github.com/en/code-security/getting-started/dependabot-quickstart-guide) (or some such dependency checker) is enabled for this repo, no Github Actions to check PRs, nothing. Needs a bunch of work and we can probably draw inspiration from out [python-package-template](https://github.com/jenstroeger/python-package-template).