Add highlightjs to examples.

docs/docs.css

@@ -937,8 +937,8 @@ h1[id] {
     white-space: nowrap;
 }
 .highlight pre code {
-    font-size: inherit;
-    color: #333; /* Effectively the base text color */
+    /*font-size: inherit;*/
+    /*color: #333; *//* Effectively the base text color */
 }
 .highlight pre .lineno {
     display: inline-block;

docs/examples.html

@@ -586,5 +586,8 @@
         </ul>
     </div>
 </footer>
+<link rel="stylesheet" href="http://yandex.st/highlightjs/8.0/styles/default.min.css">
+<script src="http://yandex.st/highlightjs/8.0/highlight.min.js"></script>
+<script>hljs.initHighlightingOnLoad();</script>
 </body>
 </html>