This website was built using GitHub Pages and Jekyll, a Ruby-based static site generator for simple, blog-focused sites like this. Once the structure of the site is set up you can simply pass the content, written in Markdown, through the Jekyll templates. A full static website is then generated and hosted completely from your GitHub repository.
There’s a lot of great documentation out there, but I found this quickstart guide especially helpful. Here’s a few other resources I liked:
You can also check out my site repository here.