docs: add missing testing doc

[legend80s]

🤔 这个变动的性质是？/ What is the nature of this change?

• [ ] 新特性提交 / New feature
• [ ] bug 修复 / Fix bug
• [ ] 样式优化 / Style optimization
• [ ] 代码风格优化 / Code style optimization
• [ ] 性能优化 / Performance optimization
• [ ] 构建优化 / Build optimization
• [x] 网站、文档、Demo 改进 / Website, documentation, demo improvements
• [ ] 重构代码或样式 / Refactor code or style
• [ ] 测试相关 / Test related
• [ ] 其他 / Other

🔗 相关 Issue / Related Issue

💡 需求背景和解决方案 / Background or solution

dumi 缺少单测指引。

📝 更新日志 / Changelog

Language	Changelog
🇺🇸 English	Add testing doc into advanced part of guide
🇨🇳 Chinese	进阶部分新增单测部分

[vercel[bot]]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
dumi	❌ Failed (Inspect)			May 31, 2024 6:49am