fix(demo): add missing route annotation that is relevant to the demo

Author: mlopezFC

src/test/java/com/flowingcode/vaadin/addons/extendedlogin/TestLoginLayoutView.java

@@ -35,6 +35,7 @@
  */
 @SuppressWarnings("serial")
 @Route(value = "extended-login/login-layout", layout = TestLoginLayout.class)
+// show-source @Route("value = "extended-login/login-layout-demo", layout = ExtendedLoginDemoView.class)
 public class TestLoginLayoutView extends Div {
 
   public TestLoginLayoutView() {