The deployment for this website is all pretty self-contained, you just need a recent emacs installation (tested with 26.3).
In order to generate the pages all you need to do is grab the sources from here and use the provided Makefile.
Emacs will take care of fetching the latest dependencies and generating the website in the public directory.
Don’t worry though, this won’t make changes to your configuration, as the Makefile ignores your own .emacs or .emacs.d/init.el and uses the provided publish.el to download packages and to build the website.
You should read publish.el if you are interested in how to emulate this setup.