I was expecting info on where the code is hosted and how one can contribute in the 'Open Source' section of the index page of the project, but there's none listed there. I eventually found my way here via Google.

I saw now there is one link to 'the github tracker' (i.e. the issues of the project's repo on GH) included in the Documentation > Need help? section of the index page, but 'help' was obviously not what I was looking for.

I'd suggest linking to the two most relevant repos – the one for the project and the other for the website documenting it, i.e. this repo – in the 'Open Source' section of index.html. I could make a pull request if you're accepting contributions? (There's, unfortunately, no README or CONTRIBUTING file with info for potential contributors and the two open issues are rather old...)