added link to docs page

Author: juelg

index.html

@@ -133,6 +133,16 @@ <h1 class="title">
                     <span>TBA</span>
                   </a>
                 </span>
+                <!-- Doc link -->
+                <span class="link-block">
+                  <a href="https://robot-control-stack.org" target="_blank"
+                    class="external-link button is-normal is-rounded is-dark">
+                    <span class="icon">
+                      <i class="fas fa-book"></i>
+                    </span>
+                    <span>Doc</span>
+                  </a>
+                </span>
                 <!-- Model Link. -->
                 <!-- <span class="link-block">
                   <a href="https://huggingface.co/Juelg"