Make the container customizable

note_kfet/templates/base.html

@@ -167,7 +167,7 @@ SPDX-License-Identifier: GPL-3.0-or-later
             </ul>
         </div>
     </nav>
-    <div class="container-fluid my-3" style="max-width: 1600px;">
+    <div class="{% block containertype %}container-fluid{% endblock %} my-3">
         {% if request.user.is_authenticated and not request.user.profile.email_confirmed %}
             <div class="alert alert-warning">
                 {% trans "Your e-mail address is not validated. Please check your mail inbox and click on the validation link." %}