adapted date format to Ymd such that its string representation is properly sortable

src/templates/index.html

@@ -40,7 +40,7 @@
                     <td scope="row"><a href="{{host}}/{{note['shortid']}}" target="_blank">{{note['shortid']}}</a></td>
                     <td>{{note['title']}}</td>
                     <td>{{note['alias']}}</td>
-                    <td><span class="note-date">{{note['lastchangeAt'].strftime('%d.%m.%Y %H:%M')}}</span></td>
+                    <td><span class="note-date">{{note['lastchangeAt'].strftime('%Y-%m-%d %H:%M')}}</span></td>
                     <td>{{note['permission']}}</td>
                     <td>{%if note['content']%}💬{%else%}❌{%endif%}</td>
                 </tr>