Summary: gives user a dialogue and they can fill out what comes after /w/
Test Plan: made some new wiki docs. played with garbage data and edit scenarios as well as vanilla create -- good ish
Reviewers: epriestley, chad
Reviewed By: epriestley
CC: aran, Korvin
Maniphest Tasks: T1360
Differential Revision: https://secure.phabricator.com/D3946
