Replace RawGit with jsDelivr

Author: jsdelivrbot

_layouts/socket_example.html

@@ -1,5 +1,5 @@
 ---
 layout: default
 ---
-<link rel="stylesheet" href="https://cdn.rawgit.com/jwarby/pygments-css/master/autumn.css"/>
+<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/jwarby/pygments-css/autumn.css"/>
 {{ content }}