More detailed docs on using non-AMD assets with ember-cli

Not having worked with javascript dependencies before, I found the current ember-cli docs confusing since they spoke of the admittedly amazing ES6 imports, except that they aren't available yet!

Hopefully this will clarify for other noobs how to handle dependencies immediately.
this statement isn't quite right, will also soon be false, @abuiles has been working on https://github.com/stefanpenner/loader.js and  https://github.com/stefanpenner/leaf to bring cross module importing to us :)

Additionally, "denanomized imports" should work correctly, like  ember-qunit and ember-data etc.