Auto-generated docs update (#793)

Co-authored-by: brokenpip3 <brokenpip3@users.noreply.github.com>

docs/index.html

@@ -213,14 +213,14 @@
 
 <div class="col-lg-3 mb-5 mb-lg-3 text-center ">
     <div class="mb-4 h1">
-        <i class="fab fa-slack"></i>
+        <i class="fas fa-brands fa-gitter"></i>
     </div>
-    <h4 class="h3">Join #jenkins-operator on Slack!</h4>
-    <p class="mb-0"><p>Chat with other users about Jenkins Operator on dedicated Slack channel.</p>
+    <h4 class="h3">Join our channel on Gitter/Matrix!</h4>
+    <p class="mb-0"><p>Chat with other users about Jenkins Operator on dedicated Gitter or if you prefer from any compatible Matrix client.</p>
 
-<p><a href="https://forms.gle/X3X8qA1XMirdBuEH7">Invite form</a></p>
+<p><a href="https://gitter.im/jenkinsci/kubernetes-operator">Gitter</a></p>
 
-<p><a href="https://virtuslab-oss.slack.com">Go to Slack</a></p>
+<p><a href="https://matrix.to/#/#jenkinsci_kubernetes-operator:gitter.im">Matrix</a></p>
 </p>
     
 </div>
@@ -232,7 +232,6 @@
 
 
 
-
       </main>
       
 <footer class="bg-dark py-5 row d-print-none">