voxconf: add signup link

Author: bastelfreak

voxconf/2026.md

@@ -28,7 +28,7 @@ title: VoxConf 2026
     </tr>
     <tr>
       <th scope="row">Register:</th>
-      <td><p class="fst-italic">**Link will be added soon**<br/>👇Scroll down for more information ⬇️</p></td>
+      <td><p class="fst-italic"><a href="https://www.meetup.com/foreman-user-group/events/313848953/">click here!</a><br/>👇Scroll down for more information ⬇️</p></td>
     </tr>
   </tbody>
 </table>