Transformers documentation translation to Chinese (Simplified)
Hi!

Let's bring the documentation to all the Chinese-speaking community :)

Who would want to translate? Please follow our [TRANSLATING guide](https://github.com/huggingface/transformers/blob/main/docs/TRANSLATING.md). Here is a list of the files ready for translation. Let us know here if you'd like to translate any and we'll add your name to the list.

Some notes:
- Add your translations to the folder [source/zh/](https://github.com/huggingface/transformers/blob/main/docs/source/zh/)
- Register your translation in [zh/_toctree.yml](https://github.com/huggingface/transformers/blob/main/docs/source/zh/_toctree.yml); please follow the order of the [English version](https://github.com/huggingface/transformers/blob/main/docs/source/en/_toctree.yml).
- Once you're finished, open a pull request and tag this issue by including #issue-number in the description, where issue-number is the number of this issue.
- 🙋 If you'd like others to help you with the translation, you can also post in our [forums](https://discuss.huggingface.co/) or tag [@espejelomar](https://twitter.com/espejelomar) on Twitter to gain some visibility.

## Get Started section

- 

- [x]  [index.mdx](https://github.com/huggingface/transformers/blob/main/docs/source/en/index.mdx). @bfss 

- [x] [quicktour.mdx](https://github.com/huggingface/transformers/blob/master/docs/source/quicktour.mdx). @bfss
This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

Please note that issues that do not follow the [contributing guidelines](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md) are likely to be ignored.