Automate slack joining process

Author: Imvedansh

src/pages/index.tsx

@@ -270,7 +270,8 @@ participation from anybody willing to work The Apache Way.
 We need folks to help with documentation, translation, promotion, and
 having someone with snazzy Web design skills would not be a bad thing!
                     </p>
-                    <a href="https://join.slack.com/t/apachecloudstack/shared_invite/zt-2aegc22z7-tPCxpptfcebTBtd59qcZSQ" className="btn btn-primary">Learn More</a>
+                    <a href="mailto:users@cloudstack.apache.org?subject=Request%20to%20Join%20Slack%20Channel&body=I%20request%20to%20join%20the%20Slack%20community.%0A%0AThanks,%0ARegards" 
+                          className="btn btn-primary"> Learn More</a>
                   </div>
                 </div>
                 <div className="col col-lg-3 col-md-6">