Feature request: deal with empty audio

[thiswillbeyourgithub]

Hi,

Great app, was waiting eagerly for something like that!

1. When the recorded audio is less than 1s, it should be ignored
2. If you set the temperature to 0, then if the replied temperature is very high IIRC it means that that whisper did a lot of amplification on the signal, it's usually the case when there is no spoken words in the section. Hence you can use that to detect when whisper heard when nothing was spoken and ignore the text.
3. Optionnal: remove silence longer than 5s in the audio, this cuts costs, avoids unecessary computation and reduces hallucination.
   Have a nice day!