Mark fields as required

source/contact.html.twig

@@ -8,22 +8,22 @@ layout: page
     <form action="https://formspree.io/{{ site.email }}" method="POST">
         <div class="form__name">
             <label for="name">Name</label>
-            <input type="text" name="name">
+            <input type="text" name="name" required>
         </div>
 
         <div class="form__email">
             <label for="email">Email</label>
-            <input type="email" name="email">
+            <input type="email" name="email" required>
         </div>
 
         <div class="form__subject">
             <label for="subject">Subject</label>
-            <input type="text" name="subject">
+            <input type="text" name="subject" required>
         </div>
 
         <div class="form__message">
             <label for="message">Message</label>
-            <textarea name="message" rows="5"></textarea>
+            <textarea name="message" rows="5" required></textarea>
         </div>
 
         <div class="form__actions">