Change the link of the logo in the mediawiki

By default, clicking the logo takes you to the main page. If you want to change which page is the main page, edit MediaWiki:Mainpage. Or to make the link go to any arbitrary URL, for Monobook skin, edit Monobook.php and find and replace data['nav_urls']['mainpage']['href'])?> with the URL of your choice and replace msg('mainpage') ?> with the desired link title.

Cite : mediawiki