Documentation: Rename installation guide from installation.html to install.html

public/documentation/index.html

@@ -33,7 +33,7 @@
     <h1>Chamilo 2.x - Documentation</h1>
     <ul>
         <li>
-            <a href="installation.html">Installation guide (EN)</a>
+            <a href="install.html">Installation guide (EN)</a>
         </li>
         <li>
             <a href="https://docs.chamilo.org/">Manuals for teachers, admins and developers (several languages available through menu)</a>

public/main/install/index.php

@@ -117,7 +117,7 @@ $institutionForm = 'My Organisation';
 $session_lifetime = 360000;
 //$installLanguage = isset($_SESSION['install_language']) ? $_SESSION['install_language'] : 'english';
 $installLanguage = '';
-$installationGuideLink = '../../documentation/installation_guide.html';
+$installationGuideLink = '../../documentation/install.html';
 
 // Setting the error reporting levels.
 error_reporting(E_ALL);