Show subtotal promotion message for free shipping rule

Show promotional message for subtotal to qualify for free shipping.

add_filter('advanced_woo_discount_rules_has_any_discount', function ($has_additional_rules, $rule){
    if($rule->rule->discount_type == 'wdr_free_shipping'){
        $has_additional_rules = true;
    }
    
    return $has_additional_rules;
}, 10, 2);