feat(templates): Add a shitty thread submission form

templates/index.html

@@ -10,5 +10,19 @@
         <li><a href="/thread/{{ thread.id }}">{{ thread.title }}</a> (posted at {{ thread.posted }})</li>
       {%- endfor %}
     </ul>
+    <hr>
+    <form action="/thread" method="post">
+      <div>
+        <label for="title">Title:</label>
+        <input type="text" id="title" name="title">
+      </div>
+      <div>
+        <label for="body">Content:</label>
+        <textarea id="body" name="body"></textarea>
+      </div>
+      <div>
+        <input type="submit" value="Submit">
+      </div>
+    </form>
   </body>
 </html>