Project Hovercards: Show Description

Summary: Fixes T15275.

Test Plan:
Project pages have "Developer > View Hovercard" button. Or hover over a project handle, I guess.

Also test for empty description and with the description field disabled.

Reviewers: O1 Blessed Committers, valerio.bozzolan

Reviewed By: O1 Blessed Committers, valerio.bozzolan

Subscribers: speck, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno

Maniphest Tasks: T15275

Differential Revision: https://we.phorge.it/D25331