Adding temporal documentation (not final)

web/index.php

@@ -1,6 +1,21 @@
 <?php
 /* For licensing terms, see /license.txt */
 
+//Classic global.inc.php file now returns a Application object
 $app = require_once '../main/inc/global.inc.php';
+
+/*
+    In order to execute Chamilo, $app->run() is needed.
+    $app->run(); shows a page depending of the URL for example when entering in "/web/index"
+    Chamilo will render the Controller IndexController->indexAction() this is because a router was assign at the end of
+    global.inc.php:
+
+        $app->get('/index', 'index.controller:indexAction')->bind('index');
+
+    The "index.controller:indexAction" string is transformed (due a controller - service approach) into
+    ChamiloLMS\Controller\IndexController->indexAction() see more at: http://silex.sensiolabs.org/doc/providers/service_controller.html
+    The class is loaded automatically (no require_once needed) thanks to the namespace ChamiloLMS added in Composer.
+    The location of the file is src\ChamiloLMS\Controller\IndexController.php following the PSR-1 standards.
+*/
 $app->run();
 //$app['http_cache']->run();