docs: fix property notation

Author: kenjis

docs/authorization.md

@@ -50,7 +50,7 @@ group elsewhere, like checking if `$user->inGroup('superadmin')`. By default, th
 ### Default User Group
 
 When a user is first registered on the site, they are assigned to a default user group. This group is defined in
-`app/config/AuthGroups::defaultGroup`, and must match the name of one of the defined groups.
+`Config\AuthGroups::$defaultGroup`, and must match the name of one of the defined groups.
 
 ```php
 public $defaultGroup = 'users';