Update index.html

Author: cabooster

index.html

@@ -89,7 +89,7 @@ <h3>Tracking in a completely unsupervised manner:</h3>
 <hr>
     <center><h1>A readily accessible and user-friendly GUI </h1></center>
 
-  <center>We have released a user-friendly graphical user interface (GUI) of UDMT to make it an easily accessible tool for ethology and neuroethology.</center>
+  <center>We have released a user-friendly [graphical user interface (GUI)](https://cabooster.github.io/UDMT/Tutorial/) of UDMT to make it an easily accessible tool for ethology and neuroethology.</center>
   </p>
   <p>
   <center><img src="https://github.com/cabooster/UDMT/blob/page/images/GUI-V2.png?raw=true" width="850" align="middle" /></center>