Add emoji_for_completion helper

app/helpers/notes_helper.rb

@@ -14,4 +14,10 @@ module NotesHelper
       "vote downvote"
     end
   end
+
+  def emoji_for_completion
+    # should be an array of strings
+    # so to_s can be called, because it is sufficient and to_json is too slow
+    Emoji::NAMES
+  end
 end