9.0.0 (2021-03-19)

feature

• Improved typescript types (2c2f30e), closes #720

BREAKING CHANGES

• It is no longer allowed to return nothing from a recipe if the target state doesn't accept undefined.
• It is no longer allowed to return arbitrary things from a recipe. Recipes should either return nothing, or something that is assignable to the original state type. This will catch mistakes with accidental returns earlier.