The site is built with hugo, which needs to first be installed. The extended version of hugo is required.
The site uses submodules to store the theme, which needs to be inited after cloneing the repo. This can be done with:
git clone https://github.com/cpp-gamedev/blog.git
cd blog
git submodule update --init --recursive
Then to run the server locally (with drafts)
hugo server -D
Then navigate to http://localhost:1313 to browse the site and see your changes. The site will automatically reload for any files changes.