Update CHANGELOG

Author: adamwathan

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Split box shadows on top-level commas only ([#7479](https://github.com/tailwindlabs/tailwindcss/pull/7479))
 - Use local user CSS cache for `@apply` ([#7524](https://github.com/tailwindlabs/tailwindcss/pull/7524))
 - Invalidate context when main CSS changes ([#7626](https://github.com/tailwindlabs/tailwindcss/pull/7626))
+- Only add `!` to selector class matching template candidate when using important modifier with mutli-class selectors ([#7664](https://github.com/tailwindlabs/tailwindcss/pull/7664))
 
 ### Changed