Disable Automated Account Creation in MediaWiki

From Zanecorpwiki

# This snippet prevents new registrations from anonymous users
# (Sysops can still create user accounts)
$wgGroupPermissions['*']['createaccount'] = false;

This will cause the 'create account' option to disappear from the the login page, but notice the 'log in / create account' (upper right hand corner while not logged in) is unchanged. To fix this, log in as a sysop and goto 'special pages->System Messages', search for 'userlogin' and change the text.

For convenience, you may want to create your user account before turning this off. Otherwise, you'll have to login as a sysop and create the user account(s).