Add new newsletter form

docs/thank-you.html

@@ -4,15 +4,28 @@ layout: default
 route: index
 ---
 
-<section class="hero is-fullheight is-success has-text-centered">
+{% include navbar.html id="ThankYou" fixed=true has_container=true boxed=true transparent=true %}
+
+<section class="hero is-large has-text-centered">
   <div class="hero-body">
     <div class="container">
-      <h1 class="title">
-        Thank you!
-      </h1>
-      <h2 class="subtitle">
-        Go back to the <a href="{{ site.url }}">homepage</a>
-      </h2>
+      <div class="columns">
+        <div class="column is-offset-3 is-6">
+          <h1 class="title">
+            📫 😃
+            <br>
+            Thanks for subscribing!
+          </h1>
+          <div class="content is-medium">
+            <p>
+              You'll occasionally receive news about new features, documentation updates, and beautiful websites made with Bulma!
+            </p>
+            <p>
+              <a onclick="window.history.back();">Go back</a>
+            </p>
+          </div>
+        </div>
+      </div>
     </div>
   </div>
 </section>