Set up CI/CD development pipeline on GitHub

[bartkl]

We'd like to have a CI/CD pipeline for developing on GitHub, so that we can have:

1. full control of this pipeline and its maintenance
2. contributors from all around the world who can safely contribute, in the spirit of open-source

What I would like to see in the development pipeline:

• Update REUSE copyright metadata (see scripts/hooks/update-copyright-metadata.sh)
• Source code formatting (lein cljfmt check)
• Run tests (lein kaocha)
• (Later) generate documentation (AsciiDoctor)

Perhaps more, and some tweaking will be necessary.

We will definitely be needing a Docker image here. The GitHub Marketplace is worth checking out too.

[bartkl]

Very good tutorial:

https://blogs.oracle.com/developers/post/building-cross-platform-native-images-with-graalvm

[bartkl]

Know that our org has added the setup-clojure Action from the Marketplace to the whitelist. So we should be ready to go.