add RoFormer Model

[JunnYu]

PR types

PR changes

Description

添加RoFormer模型

[ZeyuChen]

Please also add an example of RoFormer to paddlenlp's examples. eg.

https://github.com/PaddlePaddle/PaddleNLP/tree/develop/examples/language_model/roformer

And also please provide more pretrained weight sent to @yingyibiao, we will help you upload the pretrained weight of RoFromer.

[JunnYu]

@yingyibiao
麻烦添加一下有关的roformer权重，谢谢
https://drive.google.com/file/d/1-j_gCJ3oYjiGMG6ISfnrhQIzoe3h0bwH/view

[yingyibiao]

@yingyibiao
麻烦添加一下有关的roformer权重，谢谢
https://drive.google.com/file/d/1-j_gCJ3oYjiGMG6ISfnrhQIzoe3h0bwH/view

done

[yingyibiao]

please install pre-commit to format code style e.g.: pip install pre-commit & pre-commit install

[JunnYu]

please install pre-commit to format code style e.g.: pip install pre-commit & pre-commit install

@yingyibiao
你好，我pip install pre-commit & pre-commit install ，然后提交的时候发现没反应

[yingyibiao]

please install pre-commit to format code style e.g.: pip install pre-commit & pre-commit install

@yingyibiao
你好，我pip install pre-commit & pre-commit install ，然后提交的时候发现没反应

可以对每个文件做一些格式上的小修改，然后重新提交～

[yingyibiao]

converter这个目录可以删除，这个是遗留的老代码

[JunnYu]

@yingyibiao
done

[yingyibiao]

建议增加一个论文上的CAIL2019-SCM任务的example

[yingyibiao]

Great job!

[yingyibiao]

LGTM