add shortcut to create episode on podcast page

templates/podcast/show.html.twig

@@ -69,12 +69,20 @@
     </tbody>
   </table>
 
+  <p>
   <a href="{{ path('app_podcast_index') }}">Go back to list</a>
+  </p>
 
+  <p>
     <a
       href="{{ path('app_podcast_edit', {'id': podcast.id}) }}"
       class="btn btn-primary"
     >Edit</a>
+    <a
+        href="{{ path('app_episode_new') }}?podcast={{ podcast.id }}"
+      class="btn btn-primary"
+    >Create new episode</a>
+  </p>
 
   {{ include('podcast/_delete_form.html.twig') }}
 {% endblock %}