Update the Web Fragments doco and move it from extranet to c.a.c

This should be done once 3.7 is released.

Sam created the example doco on extranet. We need to move it to the JIRA space on confluence.atlassian.com

The doc is also missing a listring of Web Fragment conditions that are available out-of-the-box. We should simply link to the correct package in the online JIRA API's.