> Is it just me or the output PDF has quite a bit of broken pages
Nope! The breaks are really there. I guess they converted the HTML to PDF somehow and it didn't work as expected. However, in case you need it offline, the source [1] is written for zola [2] - a single-binary static site generator (of course written in Rust). You can clone the repo and run `zola serve` in it. It renders quite well.
[1] https://github.com/ralfbiedert/cheats.rs/
[2] https://www.getzola.org/