Switch topnav preCICE URL from core repo to org

Author: MakisH

_includes/topnav.html

@@ -82,7 +82,7 @@
                     <a class="no-icon nav-external" href="https://precice.discourse.group" target="_blank" data-show-count="false" aria-label="Join the discourse community"><i class="fab fa-discourse"></i></a>
                 </li>
                 <li>
-                    <a class="no-icon nav-external" href="https://github.com/precice/precice" target="_blank" data-show-count="false" aria-label="Star precice/precice on GitHub"><i class="fab fa-github"></i></a>
+                    <a class="no-icon nav-external" href="https://github.com/precice" target="_blank" data-show-count="false" aria-label="Star precice/precice on GitHub"><i class="fab fa-github"></i></a>
                 </li>
                 <li>
                     <a class="no-icon nav-external" href="https://twitter.com/preCICE_org" target="_blank" data-show-count="false" aria-label="Follow us on Twitter"><i class="fab fa-twitter"></i></a>