R1:660747d64922

Make links to hidden comments work (Fixes T11117)

Summary: This Fixes T11117.

Test Plan:
- Ran `bin/celerity map`
- Followed STR in T11117.
- Now it works.

Reviewers: epriestley, #blessed_reviewers, chad

Reviewed By: epriestley, #blessed_reviewers, chad

Subscribers: chad, Korvin

Maniphest Tasks: T11117

Differential Revision: https://secure.phabricator.com/D16256