Added new features:

• Downloading by volume. Use the -v flag in the dl subcommand for downloading volume. Also available in interactive mode.
• Saving search results in JSON format. Use the -o flag in the find subcommand to save search results in the Search-Results_*.json file.
• Added a rate limiter for the API. Now you see fewer errors.

These features were implemented by @BelardoA https://github.com/BelardoA . Thanks for contributing!