Observability task: improve the document of log configuration

- [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：
在[Dubbo website](https://github.com/apache/dubbo-website)中完善日志相关文档，包含如何优雅的日志打印比如分层打印框架日志，性能日志等

en:
Improve log related documents on the [Dubbo website](https://github.com/apache/dubbo-website), including how to print logs gracefully, such as hierarchical printing framework logs, performance logs, etc.