FYI: If you put a bunch of text files (with formatting in the markdown convention) in a folder, that is, a github repo and add _config.yml with the octobook-book-2018 remote theme you will get a book "automagically" build (and hosted on a content delivery network) all for free thanks to GitHub (Pages). See https://github.com/octobook and for more details the talk notes on octobook https://github.com/geraldb/talks/blob/master/octobook.md Cheers. Prost.
TIL there are not just Wikibooks [1] but also Wikipedia books [2]. TFA is about the latter (but calls them Wikibooks).
I guess the difference is that Wikibooks are written from scratch and expected to have a coherent structure like a normal book, whereas Wikipedia books only need to link to existing Wikipedia articles, so they're easier to create.
This is a fascinating idea, which rings very similar to the idea of "trails" as described in Vannevar Bush's "As We May Think"(https://www.theatlantic.com/magazine/archive/1945/07/as-we-m...): the creative forging of trails through existing works as a way to generate new knowledge, except in this cases its done automatically by a machine! Even more interesting would be an editor interface to allow a natural intelligence (ie a person) to make edits in the trail, rather than in the ultimately-produced book.