This site is now shut down. When I created it, I wrote:

It's hosted on App Engine and without a domain name so it doesn't require any money to keep running and minimizes risks of it shutting down due to lack of funds or forgotten domain name renewals.

I wanted to write code once and have it work forever. Well, what I didn't anticipate is that App Engine would require occasional maintenance on the project owner's behalf, to update to changes in App Engine. I have no interest in doing that. Sorry. Please use Google search to find contributing information, or just add contributing info to your project's site or Github repo.