Add Superhighway: web search API for AI agents and RAG pipelines

[patwalls]

What's being added

Superhighway (https://superhighway.walls.sh) — a web search API designed for AI agents and RAG retrieval pipelines.

Fits alongside existing tools like LangChain, LlamaIndex, and Unstructured in the Tools section, since Superhighway is the web retrieval layer: agents call it to fetch fresh web results, scrape pages, or synthesize a multi-page research answer in a single API call.

Why it belongs here:

• Provides the retrieval step in a RAG pipeline from the live web (vs. a static vector store)
• Returns structured results: title + URL + description (search), or full cleaned markdown text (scrape/research)
• Integrates directly with LangChain, LlamaIndex, LangGraph, CrewAI, and other agent frameworks (integration guides)
• Supports both a free API key tier and x402 USDC pay-per-call (agents can pay autonomously, no signup)

No changes to existing content — single addition to the Tools section.