I'll be honest, it would be weird for you to work on this if you're not me... but since you're here: you'll need nix for this build system to work out of the box. Once you have it:
To build the website, try:
$ nix build
You can build the resume only with $ nix build .#resume but that would make
little sense since it is recursively built for use by the website. If said
website is at result/, the resume is at result/louis_feuvrier-resume.pdf
To hot-reload the website in your browser while iterating on it, try:
$ nix develop
$ cd web/
$ zola serve &
$ $BROWSER http://127.0.0.1:1111