[Mediawiki-l] What is or where to find file LocalConfig.php ?

[Francois Colonna]

Hello,

at the bottom of page
http://www.mediawiki.org/wiki/Extension:AutoExtensionLoader 

it is said : 
        2. Add a call to it at the end of LocalConfig.php:
        require_once("$IP/extensions/AutoExtensionLoader/AutoExtensionLoader.php");

I checked all my mediawiki directory I have no such LocalConfig.php
file.

Is the name incorrect ? Where do I need to put that line of php code ?

Thanks for helping.
Francois Colonna