Update README.md

Author: Matheus2212

README.md

@@ -4,7 +4,7 @@ Class that controls Friendly URL. It is focused on SEO best practices.
 ---
 
 ## Overview
-This class __construct method accepts a initial $url to work with. Please note that the $url informed will be used as the ROOT URL (like the `<base href="$url" />` HTML tag).
+This class __construct method accepts a initial $url to work with. Please note that the $url informed will be used as the ROOT URL (like the `<base href="<?php echo $url ?>" />` HTML tag).
 
 It can also be omitted, but then the script will try to use $_SERVER values to build the URL.