download_file:
  description: Downloads a file to the download location.
  fields:
    url: 
      description: The URL of the file to download.
      example: 'http://example.org/myfile'
    subdir:
      description: Download into subdirectory.
      example: 'download_dir'
    filename:
      description: Determine the filename.
      example: 'my_file_name'
    overwrite:
      description: Whether to overwrite the file or not.
      example: 'false'