Update header.html

Author: msm-sardar

_includes/header.html

@@ -13,7 +13,7 @@
           <a class="nav-item nav-link text-primary" href="{{ site.baseurl }}/people">People</a>
           <a class="nav-item nav-link text-primary" href="{{ site.baseurl }}/publications">Publications</a>
           <a class="nav-item nav-link text-primary" href="https://swolfpy.readthedocs.io/en/latest/" target="_blank">Documentation</a>
-          <a class="nav-item nav-link text-primary" href="https://pypi.org/project/swolfpy/" target="_blank">Installation</a>
+          <a class="nav-item nav-link text-primary" href="https://swolfpy.readthedocs.io/en/latest/installation.html" target="_blank">Installation</a>
           <a class="nav-item nav-link text-primary" href="{{ site.baseurl }}/contact">Contact</a>
         </div>
       </div>