Document how to use MediaWysiwygFilter on custom migrations

Thanks for this module, it's saved me a lot of time.
Just to add to this discussion, I've used the media_wysiwyg_filter standalone in a custom migration and had to alter the plugins to stop depending on d7_file_plain:image:public and d7_file_entity:image:public which I don't use, like so:

/**
 * Implements hook_migration_plugins_alter().
 */
function my_module_migration_plugins_alter(array &$migrations) {
  $migration_ids = [
    'upgrade_d7_node_complete_article',
    'upgrade_d7_node_complete_page,
  ];
  $dependencies_to_remove = [
    'd7_file_plain:image:public',
    'd7_file_entity:image:public',
  ];
  foreach ($migration_ids as $migration_id) {
    $dependencies = $migrations[$migration_id]['migration_dependencies'];
    $dependencies['required'] = array_diff($dependencies['required'], $dependencies_to_remove);
    $migrations[$migration_id]['migration_dependencies'] = $dependencies;
  }
}

Then used the process plugin normally on the migration:

  body/value:
    -
      plugin: get
      source: body/0/value
    -
      plugin: media_wysiwyg_filter
      view_mode_matching:
        default: full
      media_migrations:
        - upgrade_d7_media_images
      file_migrations:
        - upgrade_d7_file

Worth saying that I had much better results in terms of visualization with entity embed than media embed, but the transformation worked very well.