Comment the functions from _utils

[brianRey2017]

• [ ] download_file_content_as_text
• [ ] download_file
• [ ] download_from_drive
• [ ] download_file_over_ftp
• [ ] download_bigger_file
• [ ] extract_zip
• [ ] extract_tar
• [ ] mkdir_unless_exists
• [ ] show_images
• [ ] show_subset
• [ ] show_dataset