Update changelog

Author: davidsemakula

CHANGELOG.md

@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 [Unreleased]
 
+### Added
+- Add `#[ink::interface]` attribute - [#2648](https://github.com/use-ink/ink/pull/2648)
+
 ### Fixed
 - `name` override fixes for message id computation and trait definitions - [#2649](https://github.com/use-ink/ink/pull/2649)