DOC: add cl

CHANGELOG.md

@@ -17,7 +17,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * `form_elements.make_form_modal` and
   `form_elements.make_scripting_submission_button` functions to create a form
   modal and an SSS submission button, respectively.
-
+* Allow to supply a function that creates the form instead of a config to
+  create_show_form_callback
 ### Changed (for changes in existing functionality)
 
 ### Deprecated