feat: add polymarket-market-data (lightweight) + binance-skills-hub

Highlights

This release adds two finance-focused skill packages:

1. polymarket-market-data
2. binance-skills-hub

polymarket-market-data (lightweight subset)

polymarket-market-data is a lightweight subset of the official polymarket-agent-skills.

It focuses only on no-auth, read-only market intelligence:

• Gamma discovery (events, markets, tags, sports)
• CLOB public pricing reads (price, midpoint, spread, history)
• Public WebSocket streams (market + sports)

It is intentionally minimal for analytics/research use cases and excludes authenticated workflows, order execution, and transaction flows that the full official polymarket-agent-skills can cover.

New: binance-skills-hub

Added support for Binance Skills Hub, an open skills marketplace for crypto agent capabilities across centralized and decentralized use cases.
This expands available integrations for token search, trading-related workflows, wallet/signal monitoring, and broader ecosystem interoperability.