Add CHANGELOG entry

CHANGELOG.md

@@ -34,6 +34,21 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Added `STTMuteFrame`, a control frame that enables/disables speech
   transcription in STT services.
+- Added conversation flow management system through `FlowState` and `FlowManager` classes.
+  This system enables developers to create structured, multi-turn conversations using
+  a node-based state machine. Each node can contain:
+  - Multiple LLM context messages (system/user/assistant)
+  - Available functions for that state
+  - Pre- and post-actions for state transitions
+  - Support for both terminal functions (stay in same node) and transitional functions
+  - Built-in handlers for immediate TTS feedback and conversation end
+- Added `NodeConfig` dataclass for defining conversation states, supporting:
+  - Multiple messages per node for complex prompt building
+  - Function definitions for available actions
+  - Optional pre- and post-action hooks
+  - Clear separation between node configuration and state management
+- Added foundational example `25-conversation-flow.py` showing how to use the new
+  conversation flow functionality.
 
 ## [0.0.48] - 2024-11-10 "Antonio release"