The type of change "improvement" was removed?

[Chia-ChunHsu]

I update the cz-cli version from 4.03 to 4.12, then I found that the improvement type was missed?

Has it just been deleted or been combined to another commit type?

(Sorry for my poor English)

[Chia-ChunHsu]

I found that
commitizen/conventional-commit-types#16

Thanks~~~