Documentation or Example

Problem/Motivation

Hello, is there any guide how to add new content in modal ?

I am not really sure how to make this work:

To add an action for a 'modal' entity form, add the following to your module.action.yml file:

```
your_module.your_link:
route_name: modal_entity_form.add
route_parameters:
entity_type: foo
bundle: bar
form_mode: baz
appears_on:
- some.router.link
title: 'Add entity'
class: 'Drupal\modal_entity_form\Menu\LocalActionWithModal'

Can anyone provide more details , step by step for "article" for example ?