[HELP-WANTED] Add change log

[JoshOY]

Is your feature request related to a problem? Please describe.
It is not-related to any feature but for better management of this project.
Currently we don't have a clear log on the history of enhancements, bug fixes, new features & breaking changes.
A changelog file is needed to record these information down.

Describe the solution you'd like
Create & maintain a new CHANGELOG or CHANGELOG.md file in the root directory of this project.

Try automatically manage this file with some tools like commitizen.

[JoshOY]

https://github.com/conventional-changelog
This can also be helpful.