At the moment, a user cannot use Content Assist for Angular.js by default, because the according Tern module isn't turned on by default.
So, users have to do the following set up in order to use it:
Add 'AngularJS module to Tern in order to make anguler-related stuff enabled on the project. In order to do that you should enable 'JBoss Experimental configuration' in Window -> Preferences -> General -> Capabilities first, then enable 'angilar' module in Project properties -> Tern -> Modules.
We shall detect the angular usage on a project and turn that module on automatically.
We should ask user to enable AngularJS support for the project when an html file with angularJS usage is opened with JBT HTML Editor (if not enabled yet):