[ST] Add st cli

[CLI]Update tags of pretrained_models.

[CLI][CLS]Add audio classification cli.

update_bs

[setup.py]change the required py_version

[demos][docs]update demos readme

[asr] update librispeech asr1 transformer result

Update README.md

Add more explanation of the demos readme.

[demos]rm big sources in demos

[CLI] remove the os.chdir