Update CHANGELOG

Author: matthiasgeihs

packages/shield-controller/CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - Add two new controller state metadata properties: `includeInStateLogs` and `usedInUi` ([#6504](https://github.com/MetaMask/core/pull/6504))
+- Add signature coverage checking ([#6501](https://github.com/MetaMask/core/pull/6501))
 
 ### Changed