feat: Semantic Search Navigation for Long Documentation Pages

[crazygo]

Let me draft the GitHub issue:

Title: feat: Semantic Search Navigation for Long Documentation Pages

Is your feature request related to a problem? Please describe.

When browsing long documentation pages (e.g., https://openresty.org/cn/components.html), it's challenging to locate specific content without knowing exact keywords. Traditional Ctrl+F search fails when users don't know the precise terms, making content discovery inefficient and time-consuming.

Describe the solution you'd like

Implement a semantic search navigation that:

• Allows natural language queries (e.g., "find scripting related components")
• Shows a floating search box with real-time results
• Highlights relevant sections while dimming others
• Provides quick-jump links to matching content areas
• Uses embeddings/NLP to understand content context

Describe alternatives you've considered

• Browser's built-in find (Ctrl+F) - Too rigid, requires exact matches
• Table of contents - Not granular enough for specific content
• Full-text search engine - Overkill for single-page navigation

Additional context

• Target use case: Technical documentation and long-form content
• Should work client-side to maintain page performance
• Could leverage existing NLP libraries like TensorFlow.js for lightweight semantic matching

Would you like me to adjust any part of this issue?