Slides use the reveal.js JavaScript presentation framwork. There is an "index" slide that links to available presentations.
Handouts are made using (most) of the reveal.js CSS. It simplifies the HTML structure a bit and overrides some of the CSS for better print layout.
You need Node installed. It can be installed via nvm or asdf, both of which can be installed via Homebrew.
npm install
npm start
Just open the html file and print.