Update Ember plugin docs.
Update Ember plugin docs.

This is based on the Angular docs, but suited for Ember / Ember CLI.

getsentry/raven-js,Mappy/raven-js,getsentry/raven-js,getsentry/raven-js,Mappy/raven-js,housinghq/main-raven-js,getsentry/raven-js,Mappy/raven-js,housinghq/main-raven-js,housinghq/main-raven-js