R1:f182d735e9e5

Make fork more prominent in edit cases

Summary: since you can't edit text the correct move is to fork. Make that abundantly clear.

Test Plan: it was clear to me

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T1826

Differential Revision: https://secure.phabricator.com/D3593