This was a simple project for PLV Media. We had a ~125 page guide, and preferred editing it in google docs, but wanted a more mobile-friendly browsing solution.
This is what I came up with. It's not terribly efficent, robust, or extensible—it was made to fit a purpose, and it fills its niche.
Effectively, it just parses the output from Download -> As Web Page and turns it into Jekyll-compatible markdown. Hosting is easy with GitHub Pages after that.
Feel free to copy, use, distribute, or otherwise use the code.