[Docathon][Add Inplace CN Doc No.9]

[Keywennn]

描述：
为cauchy_添加中文文档

增加：
cauchy__cn.rst文件

修改：
在Overview_cn.rst中新增新添加的API相关信息（均在“tensor 数学操作原位（inplace）版本”标题下）

issue:#7090

英文文档：
cauchy_: https://www.paddlepaddle.org.cn/documentation/docs/en/develop/api/paddle/cauchy__en.html

@sunzhongkai588

[paddle-bot]

感谢你贡献飞桨文档，文档预览构建中，Docs-New 跑完后即可预览，预览链接：http://preview-pr-7231.paddle-docs-preview.paddlepaddle.org.cn/documentation/docs/zh/api/index_cn.html
预览工具的更多说明，请参考：飞桨文档预览工具

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

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[Keywennn]

CLA签署失败：没有设置正确的git email