[documentation] add a changelog

[Ayc0]

When upgrading this library, it's a bit hard to understand what changed without a changelog.

Could one be added, either with a CHANGELOG file, or via GH releases?

(And also, could tags be generated when new versions are released to NPM so that it could be easier to view with https://github.com/arcanis/clipanion/compare 2 differents tags to have a quick overview of what has changed?)

[gperdomor]

Please add a changelog 🙏🏻...