Might as well take IE8 and below support for 3 lines of code.

_layouts/default.html

@@ -12,6 +12,10 @@
     <meta name="description" content="{{ site.description }}">
     <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
 
+    <!--[if lt IE 9]>
+      <script src="http://html5shiv.googlecode.com/svn/trunk/html5.js"></script>
+    <![endif]-->
+
     <link rel="stylesheet" type="text/css" href="{{ site.baseurl }}/style.css" />
 
     <!-- Created with Jekyll Now - http://github.com/barryclark/jekyll-now -->