traget help link on dowload page to Github discussions (#56)

diff --git a/website/download.ejs b/website/download.ejs
index d7e8257..bce2813 100644
--- a/website/download.ejs
+++ b/website/download.ejs
@@ -87,7 +87,7 @@
                                                     </span>
                                 </div>
                                 <div class="col-md-11 col-9">
-                                    Ask your question on  <a href="https://stackoverflow.com/questions/tagged/streampipes">Stack Overflow</a>.
+                                    Ask your question on our <a href="https://github.com/apache/streampipes/discussions">GitHub discussion</a> page.
                                 </div>
                             </div>
                         </li>