Add `CHANGELOG.md`, `CONTRIBURING.md`, and `CODE_OF_CONDUCT` files

As the title states.

CHANGELOG.md

+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to a versioning scheme similar to Matlab, with versions based on the release year.
+
+## [Unreleased]
+
+### Added
+
+- Add `CHANGELOG.md`, `CONTRIBURING.md`, and `CODE_OF_CONDUCT` files (!6)
+- Unit testing for most used functions in binding (!4)
+
+### Changed
+
+- Complete rework of binding using `betterproto` for a pure Python implementation (!4)
+
+## [2023b] - 2023-11-16
+
+### Changed
+
+- Improved README.md
+
+## [2023a] - 2023-06-21
+
+### Added
+
+- Better wheel generation with multiple Python versions supported
+
+### Fixed
+
+- many minor bugs in binding
+
+## [2022a] - 2022-06-15
+
+### Changed
+
+- Modernize build system
+
+## Previous versions
+
+- No changelog available
\ No newline at end of file