message: Add a "message received" screen to the contact form.
diff: </div>
  <section class="card shadow-xl mb-32 mx-8">
  + {#if isEmailSent}
  + <h3 class="text-center mb-8">Thank you for your message</h3>
  + <p class="text-center">
  + We received your message. Our team will take a look and get back to you as
  + soon as possible.
  + </p>
  + <div
  + style="height: 45rem; background-image: url(/images/illustration-crop.jpg);"
  + class="hidden bg-right-top md:block"
  + />
  + {:else}
  <form on:submit|preventDefault={handleSubmit} novalidate>
  <h3 class="text-center mb-8">Send us a message</h3>
  <ul>
  >
  </li>
  <li>
  - <button type="submit" class="btn" disabled={isFormDirty && !isFormValid}
  - >Send message</button
  + <button
  + type="submit"
  + class="btn"
  + disabled={isFormDirty && !isFormValid}>Send message</button
  >
  </li>
  </ul>
  <p>Thank you! We'll get back to you soon.</p>
  {/if}
  </form>
  + {/if}
  </section>
  