Bump version to 0.4.3

Bump version to 0.4.2

Bump version to 0.4.1

Fix links in changelog

Bump version to 0.3.3 and adjust changelog

Add some additional tests for `Option<NonZero*>`

Bump version to 0.3.1

Fix typo in CI script

Prepare for 0.2.0 release

Add CHANGELOG.md