To contribute to the website, you'll first need to install the extended version of Hugo.
The Hugo install page has instructions for different platforms and installers; make sure you end up with the extended version.
On Linux it may be easiest to pick up a tarball of the latest extended version from the release page and install it per https://gohugo.io/getting-started/installing/#install-hugo-from-tarball.
Next, clone this repository, and install the theme:
git submodule update --init --recursive
The development web server is started with:
make serve
If you don't have make available (e.g., on Windows), use this instead:
hugo server
after which the site should be served at http://localhost:1313.
You'll see
error: failed to transform resource: TOCSS: failed to transform "style.sass"if you don't have the Hugo extended version.