RHDEVDOCS-5441: add link for previews

Author: mramendi

scripts/ocpdocs/_previewpage

@@ -153,7 +153,26 @@
               </p>
             </div>
           </div>
-        </div>        
+        </div>
+        <div class="row">
+          <div class="col-sm-6 text-center">
+            <h2>OpenShift Pipelines</h2>
+            <div class="list-group">
+              <p>
+                <a
+                  role="button"
+                  class="btn btn-primary"
+                  href="/openshift-pipelines/latest/pipelines/understanding-openshift-pipelines.html"
+                >
+                  <i class="fa fa-arrow-circle-o-right"></i> Serverless</a
+                >
+              </p>
+              <p class="list-group-item-text">
+                Standalone OpenShift Serverless documentation.
+              </p>
+            </div>
+          </div>
+        </div>
       </div>
     </div>
   </body>