Update Favicon

Update favicon to higher resolution version.

Author: mzagaja

_includes/head.html

@@ -3,7 +3,8 @@
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1">
 
-  <link rel="icon" type="image/png" href="/favicon.png">
+  <link rel="shortcut icon" href="/favicon.ico">
+  <link rel="apple-touch-icon-precomposed" href="/favicon-180.png">
 
 
   <title>{% if page.title %}{{ page.title }}{% else %}{{ site.title }}{% endif %}</title>