Update ga code to use the enhanced link attribution feature

index.html

@@ -12,9 +12,10 @@
       })(window,document,'script','//www.google-analytics.com/analytics.js','ga');
     
       ga('create', 'UA-8268430-9', 'plataformatec.com.br');
+      ga('require', 'linkid', 'linkid.js');
       ga('send', 'pageview');
-    
     </script>
+    
     <script type="text/javascript">
       (function(d,s,i,r) {
         if (d.getElementById(i)){return;}
@@ -23,7 +24,9 @@
         e.parentNode.insertBefore(n, e);
       })(document,"script","hs-analytics",300000);
     </script>
+    
     <script src="documentup.min.js"></script>
+
     <script>
       DocumentUp.document({
         repo: "plataformatec/devise",