update link

Author: wenbowen123

index.html

@@ -89,7 +89,7 @@ <h1 class="title is-1 publication-title" style="font-size:36px;">FoundationStere
               </span>
               <!-- Code Link. -->
               <span class="link-block">
-                <a href="" class="external-link button is-normal is-rounded is-dark">
+                <a href="https://github.com/NVlabs/FoundationStereo/tree/master" class="external-link button is-normal is-rounded is-dark">
                   <span class="icon">
                       <i class="fab fa-github"></i>
                   </span>