mark-down.hbs

{{textarea value=markdown rows="10" class="form-control"}}

mark-down.js

import Ember from 'ember';

export default Ember.Component.extend({
	init: function() {
		this._super();

		// Showdown is available
		/* jshint ignore:start */
		this.set('showdownConverter', new Showdown.converter());
		/* jshint ignore:end */
	},
	
	whereYouWouldInitJqueryStuff: function() {
		//this.$('.yourInput').tagsInput();
	}.on('didInsertElement')
	
	// striped some unimportant code here, basically this component shows a preview of rendered markdown
});

some-template.hbs

{{mark-down markdown=model.description}}