Colorize monospaced links correctly in Remarkup

Summary:
This feature isn't necessarily intentional, but might as well make it work better.

Fixes T2201.

Test Plan: Verified that [[link | `name`]] renders in blue.

Reviewers: chad, btrahan, vrana

Reviewed By: chad

CC: aran

Maniphest Tasks: T2201

Differential Revision: https://secure.phabricator.com/D4217