Starting the Calendar user guide
Summary: Ref T7951, Starting the Calendar user guide
Test Plan: Go to Diviner → Phabricator User Docs → Calendar User Guide, read about how fabulous the Calendar application is.
Reviewers: epriestley, Blessed Reviewers
Reviewed By: epriestley, Blessed Reviewers
Subscribers: epriestley, Korvin
Maniphest Tasks: T7951
Differential Revision: https://secure.phabricator.com/D13496