add classes to integrate with new bit-docs-prettify, with prism

Author: Christopher Baker

demo_frame.stache

@@ -11,6 +11,6 @@
 		<pre class="prettyprint"></pre>
 	</div>
 	<div class="tab-content" data-for="js">
-		<pre class="prettyprint lang-js"></pre>
+		<pre class="line-numbers language-js"></pre>
 	</div>
-</div>
+</div>

demo_tpl.js

@@ -11,6 +11,6 @@ module.exports = `
 		<pre class="prettyprint"></pre>
 	</div>
 	<div class="tab-content" data-for="js">
-		<pre class="prettyprint lang-js"></pre>
+		<pre class="line-numbers language-js"></pre>
 	</div>
 `;