Link the join us button on the SEF engineering team page (#1602)

engineering-team/index.html

@@ -53,7 +53,7 @@ <h1 class="text-roboto text-capitalize pb-2">SEF Engineering Team</h1>
                             With our community being active through various mediums such as standup meetings, knowledge
                             sharing sessions and communication platform groups, you will soon be exposed to the startup
                             culture, the various practices and procedures involved with contributing to projects. </p>
-                        <a href="/join-us.html">
+                        <a href="https://handbook.sefglobal.org/engineering-team/team/" target="_blank">
                             <button class="btn btn-default text-uppercase mt-3" href="examples">Join us</button>
                         </a>
                     </div>