Update index.html

Author: rocky

index.html

@@ -46,7 +46,7 @@ <h2>
 
       <p><a href="https://github.com/mathics/Mathics/">Github</a></p>
 
-      <p><a href="https://github.com/mathics/Mathics/wiki/Installing">Installation guide</a></p>
+      <p><a href="https://github.com/mathics/Mathics/wiki/Installing-and-Running">Installation and Running Guide</a></p>
 
       <h2>
       <a id="documentation" class="anchor" href="#documentation" aria-hidden="true"><span class="octicon octicon-link"></span></a>Documentation</h2>