docs : add html5shiv to index

index.html

@@ -8,6 +8,8 @@ layout: nil
   <meta charset="utf-8" />
   <title>{{ site.name }}</title>
   
+  <!--[if lt IE 9]><script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script><![endif]-->
+  
   <link rel="stylesheet" href="css/style.css" type="text/css" media="screen" />
 
   <style media="screen">