Add VAD segmentation and Docker ENV defaults

bridge/.env.example

@@ -23,3 +23,12 @@ PCM_SAMPLE_RATE=16000
 MAX_SESSION_BYTES=16000000
 WAV_SEGMENT_MAX_BYTES=20971520
 WAV_KEEP_FILES=10
+
+VAD_ENABLED=true
+VAD_DIR=/data/vad
+VAD_KEEP_FILES=100
+VAD_PREROLL_MS=1000
+VAD_POSTROLL_MS=1000
+VAD_START_THRESHOLD=900
+VAD_STOP_THRESHOLD=600
+VAD_MIN_SPEECH_MS=300