Language en support

```
python speech_to_srt.py \
> -i /mnt/e/S2T/1.mp4 \
> -o /mnt/e/S2T/1.srt \
> -lang en \
> -r \
> -f 50

usage: speech_to_srt.py [-h] [--lang LANGUAGE] -i INPUT_NAME -o OUTPUT_NAME [-r] [-f SOUND_FRAME]
speech_to_srt.py: error: unrecognized arguments: -lang en
```

Hello,
When I run command using -lang en, it shows above error.
English is not supported?