Update changelog, Update docs JSON

docs/documentation/helpers/typography-helpers.html

@@ -334,6 +334,10 @@ breadcrumb:
     <td><code>is-italic</code></td>
     <td>Transforms <strong>all characters</strong> to <strong>italic</strong></td>
   </tr>
+  <tr>
+    <td>{% include elements/new-tag.html version="0.9.3" %}<code>is-underlined</code></td>
+    <td><strong>Underlines</strong> the text</td>
+  </tr>
   </tbody>
 </table>