Add missing heading to changelog

Author: adamwathan

CHANGELOG.md

@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [3.4.7] - 2024-07-25
 
+### Fixed
+
 - Fix class detection in Slim templates with attached attributes and ID ([#14019](https://github.com/tailwindlabs/tailwindcss/pull/14019))
 - Ensure attribute values in `data-*` and `aria-*` modifiers are always quoted in the generated CSS ([#14037](https://github.com/tailwindlabs/tailwindcss/pull/14037))