Add Users API documentation

Fixes #97
Fix uses of 'product' instead of 'user' in users API
Fix syntax errors in user documentation
Add states documentation

Fixes #100
1.0, 1.1 release notes
1.1.4, 1.2.0 release notes
More updates to push guides
Drop unneeded integration pages
Move release notes to developer guide
Replaced shell with bash blocks
Replace ~~~ with the correct *** style for legacy INFO blocks
Fixed additional NOTE and INFO
Moved release notes into their own section
Fix up and change order in menu links
More release notes clean up
Remove current release notes
Renamed to .md extension
Automatically open version menu for release notes
Do not show 2.0.0 release notes in navigation until actual release
Fixed front page guide links