Update Online Documentation

Hi,

A little update for the v3 user-guide :

https://ellislab.com/expressionengine/user-guide/installation/best_practices.html

Replace : Open system/expressionengine/config/config.php (or whatever you have renamed the system folder to) and update the URL to the admin.php file

With : Open system/user/config/config.php (or whatever you have renamed the system folder to) and update the URL to the admin.php file

Thank you !