For people who didn't understand what this is doing - it's using client-side JS to load the markdown files from GitHub, compiling it to HTML and displaying it on the browser.
Looks like the advantage of this is that it's a one-time setup - you don't need to build the files every time you commit, you can add your markdown files on GitHub and it automatically gets 'added' to your blog.
The downside of this is that this makes RSS feeds impossible, and non-JS users will suffer.