code: def docs(root_url, path):
      
      root_url = root_url.rstrip('/')
      path = path.lstrip('/')
      if root_url == OLD_ROOT_URL:
          return 'https://docs.taskcluster.net/{}'.format(path)
      else:
          return '{}/docs/{}'.format(root_url, path)
docs: Generate URL for path in the Taskcluster docs.