Much of the book was wrapped at around 80 columns, but let's make this consistent.
OAuth token type doesn't work. Have to change it to PAT.
This adds instructions for building and testing books in CI on every PR and push, as well as instructions for how to automatically deploy to gh-pages on successful CI runs on `master`. Fixes #714
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Matt Ickstadt
Ganesh Prasad Kumble
Nick Fitzgerald