add pages to manage returnable products

core/templates/core/user_tools.jinja

@@ -62,6 +62,11 @@
                   {% trans %}Product types management{% endtrans %}
                 </a>
               </li>
+              <li>
+                <a href="{{ url("counter:returnable_list") }}">
+                  {% trans %}Returnable products management{% endtrans %}
+                </a>
+              </li>
               <li>
                 <a href="{{ url('counter:cash_summary_list') }}">
                   {% trans %}Cash register summaries{% endtrans %}