The author (of both the book in the demo and this software itself) is Robin Sloan. He publishes a couple email newsletters, all of which I recommend. Most recently he's been writing a development diary for a video game he's working on[0]. He published a handful of GPT-2 generated city descriptions based on a corpus of fantasy literature that was a lot of fun[1]. There's great content about the illustration style as well[2]. I recommend the follow.

[0] https://www.robinsloan.com/overworld/ [1] https://www.robinsloan.com/overworld/week/5/ [2] https://www.robinsloan.com/overworld/week/3/