Simplify dynamic navbar styling & include top app bar via jQuery

Remove the need to specify the current URL in order to style the 
selected item in the navbar

page-inserts/top-app-bar.html

@@ -0,0 +1,6 @@
+<div class="mdc-top-app-bar__row">
+    <section class="mdc-top-app-bar__section mdc-top-app-bar__section--align-start">
+        <a href="javascript:void(0);" class="demo-mensu material-icons mdc-top-app-bar__navigation-icon">menu</a>
+        <span class="mdc-top-app-bar__title">Luhn Algorithm</span>
+    </section>
+</div>