Set dlm_mailchimp_email cookie on $_GET['email'] request

dlm-cookie-on-email.php

add_action( 'init', function () {
	if ( isset( $_GET['email'] ) ) {
		$expiration_time = time() + ( DAY_IN_SECONDS * 7 );
		setcookie( 'dlm_mailchimp_email', $email, $expiration_time, '/' );
	}
} );