Karmada docs directory tidy about website HOT 5 CLOSED

I propose to add Tutorials for people to learn features step by step.

from website.

It's recommend developer guide and contributor guide splited in different sections.

from website.

Add key features section to highlight major features provided by karmada.

from website.

Good Job, looks good to me.

from website.

├── Core Concepts //核心概念
│ ├── Resource template, pp, cpp, op, cop
├── Key Features //核心功能
├── Get Started //快速上手的一个小例子
├── Installation //安装手册
├── User Guide //用户指南，用于介绍Karmada及其生态的功能
├── Administrator Guide //集群运维人员指南，用于如何迁移应用至Karmada，升级Karmada，运维Karmada
├── Developer Guide //开发者指南，用于指导如何调试Karmada、面向Karmada做二次开发、对Karmada某些功能进行自定义配置等
├── Contributor Guide //贡献者指南，用于指导新手如何给Karmada项目做贡献
├── Case Study //用户案例
├── Troubleshooting
└── FAQ
└── Reference

Generally looks good to me, please add explanatory notes in English as well, thanks

from website.