Publish changelog #57

I just picked up a new release of this package (upgrading from 0.1.x to 0.2.1), but am not sure if I picked up any breaking changes, or other notable changes. (Even if you're following semver, the spec allows breaking changes to be introduced in any 0.y.z version.*) Could you please publish a changelog with any notable changes when you publish a new release?

*Quoting https://semver.org/#spec-item-4

Major version zero (0.y.z) is for initial development. Anything MAY change at any time. The public API SHOULD NOT be considered stable.