🐛 Fixed editor autofocus when starting a new post

no issue
- we were setting the `shouldFocusEditor` value correctly but then immediately resetting it again 🙈
- updated the logic to change the value when going from new->edit as well as setting it correctly _after_ all of the controller values are reset in the `setPost` method

app/controllers/editor.js

@@ -498,12 +498,10 @@ export default Controller.extend({
             this.set('useKoenig', false);
         }
 
-        // autofocus the editor if we have a new post, this also acts as a
-        // change signal to the persistent editor on new->edit
-        this.set('shouldFocusEditor', post.get('isNew'));
-
         // don't do anything else if we're setting the same post
         if (post === this.get('post')) {
+            // set autofocus as change signal to the persistent editor on new->edit
+            this.set('shouldFocusEditor', post.get('isNew'));
             return;
         }
 
@@ -512,6 +510,9 @@ export default Controller.extend({
 
         this.set('post', post);
 
+        // autofocus the editor if we have a new post
+        this.set('shouldFocusEditor', post.get('isNew'));
+
         // need to set scratch values because they won't be present on first
         // edit of the post
         // TODO: can these be `boundOneWay` on the model as per the other attrs?