Divide Phabricator documentation into four books
Summary:
Ref T988. Divides documentation into four books:
- User: Install, configure and use Phabricator.
- Contrib: Develop and contribute to Phabricator.
- Flavor: Worldly advice.
- Generated: Generated technical documentation.
Test Plan: Generated the books and got sensible results. See screenshots.
Reviewers: chad, btrahan
Reviewed By: btrahan
CC: chad, aran
Maniphest Tasks: T988
Differential Revision: https://secure.phabricator.com/D8414