dvf-2.x-dev/dvf.routing.yml

dvf.dvf_help_controller_help:
  path: '/dvf/help/{topic}'
  defaults:
    _controller: '\Drupal\dvf\Controller\DvfHelpController::helpPage'
    _title_callback: '\Drupal\dvf\Controller\DvfHelpController::getHelpPageTitle'
  requirements:
    _permission: 'access content overview'