update CHANGELOG with CartesiaTTSService and TTSService updates

CHANGELOG.md

@@ -16,6 +16,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   processing the `StartInterruptionFrame`, so there's no need for these extra
   frames any more.
 
+### Fixed
+
+- `TTSService` end of sentence detection has been improved. It now works with
+  acronyms, numbers, hours and others.
+
+### Performance
+
+- `CartesiaTTSService` now uses websockets which improves speed. It also
+  leverages the new Cartesia contexts which maintains generated audio prosody
+  when multiple inputs are sent, therefore improving audio quality a lot.
+
 ## [0.0.36] - 2024-07-02
 
 ### Added