Explain format of paths in security.access_control

[alexislefebvre]

The following pages explain how the firewall works:

• https://symfony.com/doc/master/security/access_control.html
• https://symfony.com/doc/master/security.html#securing-url-patterns-access-control
• https://symfony.com/doc/master/best_practices/security.html

They never explain that we can use a regular expression.

For example, we use this configuration in on of our projects and it works:

- { path: ^/api/(entity1|entity2)/\d+$, methods: ['GET'], roles: ROLE_USER }

It matches /api/entity1/528491 and /api/entity2/528491.

I think that the documentation should explain that we can use regular expression in path.

[OskarStark]

This should be added to the docs 👍