add informit links

index.html

@@ -60,6 +60,9 @@ p {
   <a href='http://www.amazon.com/dp/0134190440?tracking_id=disfordig-20'><img border='1' src="cover.png" height='600'/></a>
   <br/>
   <a href='http://www.amazon.com/dp/0134190440?tracking_id=disfordig-20'><img border='0' width='150' src="buyfromamazon.png"/></a>
+  <span style='vertical-align:35%'>|</span>
+  <a href='http://www.informit.com/store/go-programming-language-9780134190440'/><span style='vertical-align:35%'>Pre-order print or e-book from publisher</span></a>
+  </div>
 </br>
 </td>
 <td width='500'>