Update CHANGELOG.md

Author: MightyCreak

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Replace `_` by `-` in the action names to be compatible with GTK action names (@MightyCreak)
 - The About dialog is now transient for the main window (@oscfdezdz)
+- Remove deprecated STOCK constants and use more modern, symbolic icons (@oscfdezdz)
 
 ### Fixed