Update head.html

Author: nipunbatra

_includes/head.html

@@ -34,7 +34,7 @@
 <link rel="stylesheet" type="text/css" href="https://fonts.googleapis.com/css?family=Roboto:300,400,500,700|Roboto+Slab:100,300,400,500,700|Material+Icons">
 
 <!-- Code Syntax Highlighting -->
-<link rel="stylesheet" href="https://gitcdn.xyz/repo/jwarby/jekyll-pygments-themes/master/{{ site.highlight_theme }}.css" />
+<link rel="stylesheet" href="{{ '/assets/css/github.css' | relative_url }}">
 
 <!-- Styles -->
 {% if site.icon != empty %}