Issue #3363711 by Chris Matthews, Nishant, Shiv_Sharma, smustgrave: Minor...

  $form['admin_theme']['use_admin_theme'] = [

    '#type' => 'checkbox',

    '#title' => t('Use the administration theme when editing or creating content'),

    '#description' => t('Control which roles can "View the administration theme" on the <a href=":permissions">Permissions page</a>.', [':permissions' => Url::fromRoute('user.admin_permissions')->toString()]),

    '#description' => t('Control which roles can "View the administration theme" on the <a href=":permissions">Permissions page</a>.', [':permissions' => Url::fromRoute('user.admin_permissions.module', ['modules' => 'system'])->toString()]),

    '#default_value' => \Drupal::configFactory()->getEditable('node.settings')->get('use_admin_theme'),

  ];

  $form['#submit'][] = 'node_form_system_themes_admin_form_submit';