Question about old lua/lua GItHub repo

[Jonathan Goble <jcgoble3@...>]

In the old github.com/lua/lua repository (back when it was just a mirror of the official tarballs), each commit's author was listed as "Lua Team committed with repogen". An example can be seen in my outdated fork of that repo: https://github.com/jcgoble3/lua-testing

What is this "repogen", and where can I read docs about it and get my hands on it? I'm interested in possibly updating my fork and maintaining it as exactly what the original lua/lua repo was (a buildable mirror of official releases), but I don't know what this "repogen" is. I've Googled the name every way I can think of, and I can only get results about some Ubuntu/Debian feature that doesn't seem relevant.

Thanks.

Jonathan Goble