[docs]: translate hertz/tutorials/example

[GuangmingLuo]

zh web page：https://www.cloudwego.io/zh/docs/hertz/tutorials/example/ zh doc：https://github.com/cloudwego/cloudwego.github.io/blob/main/content/zh/docs/hertz/tutorials/example/_index.md en folder：https://github.com/cloudwego/cloudwego.github.io/tree/main/content/en/docs/hertz/tutorials

Notes:

1. Do not change the original layout, code style or content sequence.
2. Software Translator is a tool, not god, do not use the result as the final result.
3. Translation principle: faithfulness, expressiveness and elegance.
4. Submit your PR here in this repo.

[zhoulilily]

I'd like to translate it @GuangmingLuo

[GuangmingLuo]

well done ！