Part of #1921152: META: Start providing tour tips for other core modules.
Problem/Motivation
Write tour integration for Extend admin page
Proposed resolution
Create tour yml files for required admin screens in admin/modules.
Remaining tasks
Create patch for tour integration for primary Extend page
User interface changes
New tours
API changes
None
Technical pointers when creating tour tips
See: https://drupal.org/node/1921152#tour-tips-tech-note for tech notes on making tour tips.
