The https://bors.tech web page
For more information, see the bors-ng/bors-ng repository. This repository is just a bunch of meta stuff surrounding it.
This site is generated using jekyll.
For simple changes, you can just edit right on GitHub
(GitHub's own Markdown preview will match up with the website's rendering as long as you don't use inline HTML or Liquid templates).
If you're moving a lot of stuff around, though, you'll want to install Jekyll, clone this repo, and use jekyll serve to preview it.