slack url change

Author: adumesny

demo/website.html

@@ -112,7 +112,7 @@
         </li>
         <li class="nav-item">
           <a class="nav-link" target="_blank"
-            href="https://join.slack.com/t/gridstackjs/shared_invite/zt-27q0rwf80-5vCt81Z_hfVgpRW7L17MnQ">Slack
+            href="https://join.slack.com/t/gridstackjs/shared_invite/zt-2qa21lnxz-vw29RdTFet3N6~ABqT9kwA">Slack
             <ion-icon name="logo-slack"></ion-icon></a>
         </li>
         <li class="nav-item">
@@ -308,7 +308,7 @@ <h1>Used by</h1>
             Does your company use gridstack.js? We'd love to add your logo!
             Come join our
             <a target="_blank"
-              href="https://join.slack.com/t/gridstackjs/shared_invite/zt-27q0rwf80-5vCt81Z_hfVgpRW7L17MnQ">
+              href="https://join.slack.com/t/gridstackjs/shared_invite/zt-2qa21lnxz-vw29RdTFet3N6~ABqT9kwA">
               <ion-icon name="logo-slack"></ion-icon>Slack community
             </a>
             and let us know.