More Diviner style updates

Summary: This adds a number of new styles for Diviner documentation. Not sure I've covered all the bases or wrote this in the most efficient manner, but passing it along now for early review before tightening everything up.

Test Plan: Review various class pages.

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: Korvin, aran

Differential Revision: https://secure.phabricator.com/D6888