Show same options in example as used in demo

The templateSelection option was used in the demo, but was not shown in the example code.
This commit fixes it, so that copy&pasting works as expected.

docs/_includes/examples/themes-templating-responsive-design.html

@@ -69,7 +69,8 @@ function formatState (state) {
 };
 
 $(".js-example-templating").select2({
-  templateResult: formatState
+  templateResult: formatState,
+  templateSelection: formatState
 });
 {% endhighlight %}