2.0.0

-changed python requirement from 3.7+ to 3.8+ (following Whisper)
-more reliable word-level timestamps (using Whisper's new method for word timestamps)
-transcribe() now returns WhisperResult object (allowing easier to manipulation of results)
-WhisperResult contains methods to save result as JSON/SRT/VTT/ASS
-WhisperResult contains methods to regroup segments word by word
-added Silero VAD for generating suppression mask (requires PyTorch 1.2.0+)
-improved non-vad suppression
-added visualize_suppression() for visualizing suppression based on arguments (requires Pillow or opencv-python)
-SRT/VTT/ASS outputs now all support both segment-level and word-level