[Feature] 添加中文说明文档

### 检查清单

- [ ] 1. 如果您提出的不是新功能而是问题，请在讨论区发起讨论 https://github.com/kvcache-ai/ktransformers/discussions。否则该 issue 将被关闭
- [ ] 2. 为方便社区交流，我将使用中文/英文或附上英文/中文翻译（如使用其他语言）。未附带翻译的非英文/中文内容可能会被关闭

### 需求背景

为什么说明文档全是英文的。。。

### 相关资源

_No response_

The issue names no documentation files, sections, or tests. Start by inventorying the repository’s English documentation and determining which part is in scope for Chinese translation. Done should be defined as a specified documentation set being translated and reviewed for completeness.

Written by the indexing model from the issue text.