update changelog

Author: RobinMalfait

CHANGELOG.md

@@ -7,7 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-- Nothing yet!
+### Fixed
+
+- Remove false positive warning in CLI when using the `--content` option ([#7220](https://github.com/tailwindlabs/tailwindcss/pull/7220))
 
 ## [3.0.16] - 2022-01-24