rw_config.module

<?php

/**
 * Implements hook_theme().
 */
function rw_config_theme($existing, $type, $theme, $path) {

  return [
    'rw_config_listing' => [
      'render element' => 'children',
      'template' => 'rw-config-listing', #name of the template file +.html.twig
      'variables' => [
        'data' => FALSE
      ]
    ]
  ];
}