Document adding custom validation rules for form fields

[jamesmacwhite]

As the previous plugin used the Craft Contact Form as base, you would implement custom validation rules like this:

use craft\contactform\Models\Submission;

Event::on(
    Submission::class,
    Model::EVENT_DEFINE_RULES,
    static function (DefineRulesEvent $event) {
        $event->rules[] = [['fromName', 'fromEmail', 'subject', 'message'], 'required'];
    }
);

As the plugin no longer uses the Craft Contact form, the namespace would now be: hybridinteractive\SimpleContactForm\Models\Submission;