1. removed `export2.py` from aishell recipe
2. removed `git lfs` commands for pulling `tokens.txt` from `test-onnx-export.sh`
3. applied #1152 to `export-onnx-streaming.py` and `export-onnx.py`
* copy files
* update train.py
* small fixes
* Add decode.py
* Fix dataloader in decode.py
* add blank penalty
* Add blank-penalty to other decoding method
* Minor fixes
* add zipformer2 recipe
* Minor fixes
* Remove pruned7
* export and test models
* Replace bpe with tokens in export.py and pretrain.py
* Minor fixes
* Minor fixes
* Minor fixes
* Fix export
* Update results
* Fix zipformer-ctc
* Fix ci
* Fix ci
* Fix CI
* Fix CI
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Co-authored-by: Fangjun Kuang <csukuangfj@gmail.com>
* add CTC loss option in zipformer recipe
* add ctc_decode.py
* support CTC model export, add jit_pretrained_ctc.py, pretrained_ctc.py
* update README.md and RESULTS.md
* add CI test