Enable GitHub Actions and include scalafmt
Created by: FlorianCassayre
Ensures that the project remains in a consistent state, by running the following checks in order:
- Code compiles
- Code is properly formatted
- Tests are passing
This is an opinionated change, remarks are welcome. Ideally we would want to have scalafix as well (linter), but the support for Scala 3 is partial at the time of this commit.
(main
before merging, otherwise the code style may not be consistent)