Add a remark to submit-eventListener (#1418)

Author: DigitalTimK

symfony/stimulus-bundle/2.20/assets/controllers/csrf_protection_controller.js

@@ -2,6 +2,8 @@ const nameCheck = /^[-_a-zA-Z0-9]{4,22}$/;
 const tokenCheck = /^[-_/+a-zA-Z0-9]{24,}$/;
 
 // Generate and double-submit a CSRF token in a form field and a cookie, as defined by Symfony's SameOriginCsrfTokenManager
+// Use `form.requestSubmit()` to ensure that the submit event is triggered. Using `form.submit()` will not trigger the event
+// and thus this event-listener will not be executed.
 document.addEventListener('submit', function (event) {
     generateCsrfToken(event.target);
 }, true);