add src attribute in attributes list

source/import_documentation/attributes-list.rst

@@ -191,6 +191,10 @@ List of attributes (core framework)
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    * :ref:`filter-mixin <filter-mixin>`
 
+``src-[field]``
+~~~~~~~~~~~~~~~~~
+   * :ref:`widget-mixin <widget-mixin>`
+
 ``submit-button``
 ~~~~~~~~~~~~~~~~~
    * :ref:`solid-form <solid-form>`