GlobalRoutes.yaml

-
  name: 'Package Vendor.Package'
  uriPattern: '<VendorPackageSubroutes>'
  subRoutes:
    'VendorPackageSubroutes':
      package: 'Vendor.Package'
      variables:
        'sitemapBaseUri': ''

-
  name: 'TYPO3 Neos'
  uriPattern: '<TYPO3NeosSubroutes>'
  subRoutes:
    'TYPO3NeosSubroutes':
      package: 'TYPO3.Neos'
      variables:
        'defaultUriSuffix': '.html'

PackageRoutes.yaml

-
  name:  'My Package Sitemap'
  uriPattern: '<sitemapBaseUri><node>sitemap.xml'
  defaults:
    '@package':    'TYPO3.Neos'
    '@controller': 'Frontend\Node'
    '@action':     'show'
    '@format':     'xml'
  routeParts:
    'node':
      handler:     'TYPO3\Neos\Routing\FrontendNodeRoutePartHandlerInterface'
      options:
        onlyMatchSiteNodes: true