This repository contains the contents of <JPATH_SITE>/components/com_one
.
Assuming you have a repository for your site, use these commands:
$ cd <JPATH_SITE>
$ git submodule add https://github.com/pdelbar/one-content-site-component.git components/com_one
$ git submodule init
$ git submodule update
$ git checkout master
Make sure to commit the .gitmodules file. Working with modules is explained here.