stream : update README.md + comments

examples/stream/README.md

@@ -10,7 +10,7 @@ More info is available in [issue #10](https://github.com/ggerganov/whisper.cpp/i
 
 https://user-images.githubusercontent.com/1991296/194935793-76afede7-cfa8-48d8-a80f-28ba83be7d09.mp4
 
-## Slidingwindow mode
+## Sliding window mode with VAD
 
 Setting the `--step` argument to `0` enables the sliding window mode:
 

examples/stream/stream.cpp

@@ -429,7 +429,7 @@ int main(int argc, char ** argv) {
 
     const int n_new_line = params.length_ms / params.step_ms - 1; // number of steps to print new line
 
-    const bool use_vad = n_samples_step <= 0;
+    const bool use_vad = n_samples_step <= 0; // sliding window mode uses VAD
 
     params.no_timestamps = !use_vad;
     params.no_context    = use_vad;