New logo link for Saturn (#51)

Author: jsignell

index.html

@@ -570,7 +570,7 @@ <h2 id="supported-by"><a href="#supported-by" class="link-unstyled">Supported By
                      src="_images/quansight.svg"></a>
                 </div>
                 <div class="col supporter">
-                  <a href="https://saturncloud.io/"><img src="https://www.saturncloud.io/s/wp-content/uploads/2020/10/saturncloud-logo-1.svg"></a>
+                  <a href="https://saturncloud.io/"><img src="https://saturncloud.io/icons/logo-square.png"></a>
                 </div>
               </div>
             </div>