Ember-cli-rails gem

Continuing the discussion from Build for Rails (using Ember-CLI / EmberAppKit):

I created an ember/rails app from scratch using the ember-cli-rails gem and their documentation and it worked incredibly well. But now I am attempting to use the ember-cli-rails gem in an already existing application. Does anyone know if there is documentation for this process?

So, Jason’s thing has been superceded by GitHub - thoughtbot/ember-cli-rails: Unify your EmberCLI and Rails Workflows I think.