Thanks for sharing. My humble feedback would be that the website and README would be much more helpful however if they showed pictures of sample output. That's the main thing we want to see :-)
https://puu.sh/waX9G/3d54abf030.png
https://puu.sh/waXy2/7106b4768d.png
This is on Chrome Stable, Windows. Looking in the Github rendered.
The sample book can be created by cloning the repo and running the container. (http://chrisanthropic.github.io/Open-Publisher-Documentation...)
If you want to see examples, I formatted everything here: https://www.amazon.com/Tristan-J.-Tarwater/e/B004WS3P3A/
I wonder what causes Github to mess up on just the verification messages, probably something to do with the character set.