How to contribute?

I'm using this project to move away from iText (because their html-to-pdf is barely documented, incomplete and encumbered). I have gotten much better results from this project after a day than after weeks pulling my hair out with iText. I can see myself contributing to this project, but I didn't see anything in the readme or elsewhere about how to get involved.

I'm looking for advice on developer environment setup (tooling and compilation) and project norms as far as branching, pull requests, code reviews, and prioritization.