Add a Chinese version of README

Nobody has claimed this yet.

### 📚 Documentation

These are the reasons why I want to add a Chinese version of the README：
1、Reduce language barriers and expand user base: Chinese is one of the most widely spoken languages in the world, and providing a Chinese version of the README will help a large number of Chinese developers and researchers get up to speed with PyTorch Lightning, especially those who are not familiar with English, thereby attracting more people to participate and use the project.

2、Increase the international reach of open source projects: Adding multilingual support, especially Chinese, will help PyTorch Lightning spread globally, especially in academia and industry in China and other Chinese-speaking regions. This will greatly enhance the project's user base and number of contributors.

3、Accelerate community contributions: By providing Chinese documentation, Chinese developers can better understand the project, which makes it easier to participate in the development and contribution of the project, and promotes the activity and growth of the open source community.

4、Improve learning efficiency: Providing Chinese users with native language versions of documents can significantly shorten their learning curve, allowing them to focus on the technology itself instead of spending extra time on language understanding. This will improve the efficiency of learning and research.

cc @borda

Start by locating the repository README and checking how documentation translations are organized. Create a Chinese version that stays aligned with the existing README; done means the translated README is complete, readable, and preserves the original project's information and links.

Written by the indexing model from the issue text.