R1:fb59101cde03

Use phutil_tag in Setup issue stuff

Summary: These are pretty straightforward, they just have a fair amount of instructional text with inline markup.

Test Plan: Added and viewed a UIExample.

Reviewers: vrana

Reviewed By: vrana

CC: aran

Maniphest Tasks: T2432

Differential Revision: https://secure.phabricator.com/D4686