Atlassian Connect documentation now integrated with product documentation

Read the full announcement on the Atlassian Developer blog, “Atlassian Connect content integrated with product docs”

What changed

The Atlassian Connect documentation site has been retired and all of its content has been
separated by topic and relocated to product documentation. In addition, we made a few under-the-hood improvements to the modules and JavaScript API documentation. These are now located in the Reference section.