doc: update

Author: robgee86

src/arduino/app_bricks/local_tts/README.md

@@ -1,9 +1,10 @@
 # LocalTTS Module Overview
 
-The `local_tts` module provides a completely offline text-to-speech (TTS) solution for Arduino Apps. At its core is the `LocalTTS` class, designed to convert text input into spoken audio using locally available TTS engines, ensuring privacy and low-latency performance without reliance on cloud services.
+The `LocalTTS` brick provides a completely offline text-to-speech (TTS) solution for Arduino Apps. It's designed to convert text input into spoken audio using locally available TTS engines, ensuring privacy and low-latency performance without reliance on cloud services.
 
 ## Key Features
 
 - **Offline Operation:** All speech synthesis is performed locally, ensuring data privacy and eliminating network dependencies.
 - **Multiple Language Support:** Easily switch between different languages (en, es, zh).
 - **Audio Output Formats:** Directly output synthesized speech to a Speaker instance or to WAV or PCM audio.
+- **Concurrency Control**: Limits the number of simultaneous transcription sessions to avoid resource exhaustion.