R1:1c0980a26a86

Fix two issues with Remarkup in Pholio

Summary:
Fixes T10865.

- Mock descriptions did not markup.
- Image descriptions did not get a proper container `<div />`.

Test Plan:
- Created a mock with remarkup in the mock description and in an image description.
- Viewed mock detail.
- Saw list styles render properly in both mock description and image description.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10865

Differential Revision: https://secure.phabricator.com/D15793