R1:328210a1a645

Add mobile menu to Ponder

Summary: Ref T3578, adds mobile menus to Ponder

Test Plan: Test Ponder on mobile and desktop, click in Ask Question links

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T3578

Differential Revision: https://secure.phabricator.com/D13784