feat: add nacos example

[dengWuuu]

What type of PR is this?

feat

What this PR does / why we need it (English/Chinese):

en: A more detailed case study according to the cloudWeGo documentation, adding a post request with json zh: 按照官方文档添加了更详细的案例，增加一个post请求且参数是json在服务发现中的使用

Which issue(s) this PR fixes:

https://github.com/cloudwego/hertz/issues/485

[CLAassistant]

All committers have signed the CLA.

[L2ncE]

I think you can open a new folder separately instead of directly changing the previous code.

[Skyenought]

可以用 gofumpt -l -extra -w . 整理一下代码格式

[dengWuuu]

I think you can open a new folder separately instead of directly changing the previous code.

是要把以前的两个只启动一个hertz服务器的给从以前的复制回来？，然后新建两个文件夹？一个是启动两个hertz服务器的standard_multiple_server和custom_config_multiple_server?

[L2ncE]

I think you can open a new folder separately instead of directly changing the previous code.

是要把以前的两个只启动一个hertz服务器的给从以前的复制回来？，然后新建两个文件夹？一个是启动两个hertz服务器的standard_multiple_server和custom_config_multiple_server?

原来的可以保留，新的文件夹根据你新增 example 的特性进行命名

[dengWuuu]

I think you can open a new folder separately instead of directly changing the previous code.

是要把以前的两个只启动一个hertz服务器的给从以前的复制回来？，然后新建两个文件夹？一个是启动两个hertz服务器的standard_multiple_server和custom_config_multiple_server?

原来的可以保留，新的文件夹根据你新增 example 的特性进行命名

done

[li-jin-gou]

LGTM