Adding PSR12 to documentation
Adding PSR12 to documentation

Since FriendsOfPHP/PHP-CS-Fixer#4502 has been merged and is now supported, the documentation should mention this too
phpro/grumphp,janvernieuwe/grumphp,phpro/grumphp,janvernieuwe/grumphp,veewee/grumphp,veewee/grumphp