use current best practices in docs
use current best practices in docs

Use ember modules API to import packages instead of Ember global namespace.

Use router Service instead of not-documented properties of `EmberRouter`.
Please also note the change to Ember's documentation for `EmberRouter.didTransition()`:
https://github.com/emberjs/ember.js/pull/17508

Do not use `get()`. It's not needed anymore since Ember 3.1, which was released
in April 2018.

poteto/ember-metrics,poteto/ember-metrics