docs: update CHANGELOG

Author: BriannaDelgado

CHANGELOG.md

@@ -5,6 +5,15 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- Added support for translation memories in text translation via
+  `translation_memory` and `translation_memory_threshold` parameters in
+  `translate_text()`.
+- Added `list_translation_memories()` method to the `DeepLClient` class for
+  listing available translation memories.
+- Added `--translation-memory-id` and `--translation-memory-threshold` CLI
+  arguments.
+
 ### Fixed
 - Fixed "gitlab release" CI job to explicitly set the release-cli image, avoiding issues with missing `$HOME` from the global image.