Rename some remarkup classes

Summary: Ref T5655. Rename DoorkeeperRemarkupRuleAsana and DoorkeeperRemarkupRuleJIRA for consistency.

Test Plan: N/A

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T5655

Differential Revision: https://secure.phabricator.com/D13165