R1:cb64bef3c57a

Maniphest - make instructions !assign savvy

Summary: forgot this in last diff. Ref T3937.

Test Plan: looks good

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T3937

Differential Revision: https://secure.phabricator.com/D7308