PHPStan Matchy Strings

• patterns defined in phpstan.neon, eg email-string: '^[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}$'
• function defined like:

/**
 * @param email-string $email
 */
function sendEmail(string $email): void {
    ...
}

• phpstan will then allow sendEmail("bob@example.com") but not sendEmail("bob@example")