Update understand-laravel.php

Author: aivis

src/config/understand-laravel.php

@@ -13,7 +13,10 @@
     'silent' => true,
 
     /**
-     * Specify which handler to use (sync|queue)
+     * Specify which handler to use - sync, queue or async. 
+     * 
+     * Note that the async handler will only work in systems where 
+     * the CURL command line tool is installed
      */
     'handler' => 'sync',