Summary: I'm pretty sure that `@group` annotations are useless now... see D9855. Also fixed various other minor issues.
Test Plan: Eye-ball it.
Reviewers: #blessed_reviewers, epriestley, chad
Reviewed By: #blessed_reviewers, epriestley
Subscribers: epriestley, Korvin, hach-que
Differential Revision: https://secure.phabricator.com/D9859
Summary: Fix a few "line too long" lint issues in the Diviner documentation. Also lint `*.book` files as JSON.
Test Plan: Eye-ball it.
Reviewers: epriestley, #blessed_reviewers
Reviewed By: epriestley, #blessed_reviewers
Subscribers: epriestley, Korvin
Differential Revision: https://secure.phabricator.com/D9695