To setup your machine for building the documentation you will need to install docfx. Follow their instructions here for how to setup the tool. You will not need to initialize a repository, only install it using Chocolatey, Homebrew, or manually set it up from Github. Make sure to be using the latest build of version 2.
To build the site and host it on port 8080:
cd tmg-documentation
docfx build --serve
You will then be able to view the site using a web browser going to the address
http://localhost:8080
.