observers: add LLMLogObserver and TranscriptionLogObserver

CHANGELOG.md

@@ -9,6 +9,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Added new log observers `LLMLogObserver` and `TranscriptionLogObserver` that
+  can be useful for debugging your pipelines.
+
 - Added `room_url` property to `DailyTransport`.
 
 - Added `addons` argument to `DeepgramSTTService`.
@@ -45,6 +48,10 @@ stt = DeepgramSTTService(..., live_options=LiveOptions(model="nova-2-general"))
 - Fixed an issue where `EndTaskFrame` was not triggering
   `on_client_disconnected` or closing the WebSocket in FastAPI.
 
+- Fixed an issue in `DeepgramSTTService` where the `sample_rate` passed to the
+  `LiveOptions` was not being used, causing the service to use the default
+  sample rate of pipeline.
+
 - Fixed a context aggregator issue that would not append the LLM text response
   to the context if a function call happened in the same LLM turn.
 
@@ -63,10 +70,6 @@ stt = DeepgramSTTService(..., live_options=LiveOptions(model="nova-2-general"))
 - Fixed a `STTMuteFilter` issue that would not mute user audio frames causing
   transcriptions to be generated by the STT service.
 
-- Fixes an issue in `DeepgramSTTService` where `sample_rate` passed to the
-  `LiveOptions` was not being used, causing the service to use the default
-  sample rate of pipeline.
-
 ### Other
 
 - Added Gemini support to `examples/phone-chatbot`.