Add Satelink RPC endpoint to Polygon community providers

## Provider Name
Satelink Network

## RPC Endpoint
https://rpc.satelink.network/rpc/polygon

## Website
https://satelink.network

## Status Page
https://satelink-protocol.github.io/satelink-status/

## Networks Supported
- Polygon
- Ethereum
- Arbitrum
- Base
- Solana

## Notes
Public multi-provider RPC infrastructure with autonomous routing, health monitoring, failover, and uptime optimization.