feat(contact-form): enhance validation and accessibility

src/scripts/accordion.js

@@ -2,6 +2,7 @@ document.addEventListener('DOMContentLoaded', (event) => {
   const accordionHeaders = document.querySelectorAll('.accordion-header');
 
   accordionHeaders.forEach(header => {
+    // Toggle content on click
     header.addEventListener('click', () => {
       const content = header.nextElementSibling;
       if (content.style.display === 'block') {
@@ -10,5 +11,13 @@ document.addEventListener('DOMContentLoaded', (event) => {
         content.style.display = 'block';
       }
     });
+
+    // Toggle content on Enter or Space key press
+    header.addEventListener('keydown', (e) => {
+      if (e.key === 'Enter' || e.key === ' ') {
+        e.preventDefault();
+        header.click();
+      }
+    });
   });
-});
+});