community: Spider integration

[WilliamEspegren]

Added the Spider.cloud document loader. Spider is the fastest and cheapest crawler that returns LLM-ready data.

- **Description:** Adds Spider data loader
- **Dependencies:** spider-client
- **Twitter handle:** @WilliamEspegren 

[vercel[bot]]

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

Name	Status	Preview	Comments	Updated (UTC)
langchain	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Apr 27, 2024 9:45pm

[WilliamEspegren]

@baskaryan any idea why this is failing?

[ccurme]

The docs build failed because the API reference link was missing a URL. Our docs will automatically populate API reference links so I just removed the cell.