Update changelog

Author: thecrypticace

Diff for: CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Allow arbitrary values with commas in `@apply` ([#8125](https://github.com/tailwindlabs/tailwindcss/pull/8125))
 - Fix intellisense for plugins with multiple `@apply` rules ([#8213](https://github.com/tailwindlabs/tailwindcss/pull/8213))
 - Improve type detection for arbitrary color values ([#8201](https://github.com/tailwindlabs/tailwindcss/pull/8201))
+- Support PostCSS config options in config file in CLI ([#8226](https://github.com/tailwindlabs/tailwindcss/pull/8226))
 
 ### Added