Add crumbs to calendar

Summary: Crumbs everywhere. Not sure how to better format the date, let me know.

Test Plan: Browse everything I can see in Calendar

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T4440

Differential Revision: https://secure.phabricator.com/D8265