Observability task: improve the document of log compatible trace

- [x] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.

## Describe the proposal

中文：
根据可观测性trace的具体实现情况，trace会将数据埋点到MDC中，日志这边增加配置即可

在[Dubbo website](https://github.com/apache/dubbo-website)中完善日志相关文档。

en:
According to the specific implementation of the observability trace, trace will embed the data in the MDC, and the configuration can be added to the log.

Improve log related documents on the [Dubbo website](https://github.com/apache/dubbo-website).