update changelog

Author: RobinMalfait

CHANGELOG.md

@@ -24,6 +24,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Error when registering an invalid custom variant ([#8345](https://github.com/tailwindlabs/tailwindcss/pull/8345))
 - Create tailwind.config.cjs file in ESM package when running init ([#8363](https://github.com/tailwindlabs/tailwindcss/pull/8363))
 - Fix `matchVariants` that use at-rules and placeholders ([#8392](https://github.com/tailwindlabs/tailwindcss/pull/8392))
+- Improve types of the `tailwindcss/plugin` ([#8400](https://github.com/tailwindlabs/tailwindcss/pull/8400))
 
 ### Changed