There's a submodule and in order to use the deploy.sh script to publish a new version you need it.
cd public
git submodule update --init --recursive
Hugo is not a nodejs (javascript) package it needs to be installed (to the commandline). It is written in GO, but Hugo developers maintain binaries for all platforms so it's easy to install. https://gohugo.io/
For windows install : https://chocolatey.org/packages/hugo-extended
hugo server -D
hugo
Don't forget to clone the submodule beforehand, see top of Readme
hugo
./deploy.sh