FIX: Links were not clickable after load more

The event listener function was running on the incorrect lifecycle hook.
Should've been didRender.

This commit also fixes a small bug where in some cases the screen would
not scroll all the way to the top.

assets/javascripts/discourse/components/knowledge-explorer-topic-list.js.es6

@@ -13,7 +13,7 @@ export default Ember.Component.extend({
   },
 
   // need to handle clicks here since links are in a raw view
-  didInsertElement() {
+  didRender() {
     const topicLinks = this.element.getElementsByClassName(
       "knowledge-explorer-topic-link"
     );

assets/javascripts/discourse/controllers/knowledge-explorer.js.es6

@@ -109,6 +109,8 @@ export default Ember.Controller.extend({
         selectedTopic: topicId
       });
 
+      window.scrollTo(0, 0);
+
       KnowledgeExplorer.getTopic(topicId).then(result => {
         this.setProperties({
           topic: Topic.create(result),