mention ad blockers when babel is not defined

src/components/CodeEditor/CodeEditor.js

@@ -177,6 +177,7 @@ class CodeEditor extends Component {
                     padding: 10,
                   }}>
                   {error.message}
+                  {!window.Babel && ' (try checking your ad blocker if you have one).'}
                 </pre>
               </div>
             )}