[Docs]: 官网中 Graphin 图可视分析组件 详情页面都无法打开

### 📍 Which page are you reading?

https://g6.antv.antgroup.com/manual/cases/relations

### 💭 What's on your mind?

Could be clearer / 需要更清晰的解释

### 🤔 Tell us more

https://g6.antv.antgroup.com/ 首页下滑 ，查看Graphin 图可视分析组件，点击查看详情 会跳转https://g6.antv.antgroup.com/manual/cases/relations，发现页面套娃了，单独访问就是404了

### 💡 Got any suggestions?

_No response_

Start at the G6 homepage and follow the Graphin detail link to /manual/cases/relations, then check the corresponding page behavior directly. Done means the detail link opens a valid Graphin page instead of a nested or 404 page, with the intended explanation visible.

Written by the indexing model from the issue text.