Changelog for ppad-chacha-0.2.0

# Changelog - 0.2.0 (2025-06-21) * Both the ChaCha block function and stream cipher are now total, returning values of 'Left InvalidKey' or 'Left InvalidNonce' when supplied with the corresponding bad inputs. - 0.1.0 (2025-03-09) * Initial release, supporting the chacha20 stream cipher and block function.