Missing config example for index price Driver, by default it should and connect to all available platforms

[mnaichuk]

• missing config example in the README or directly in the pkg
• DEX price feeds should have default RPC URLs, for example default chain for SyncSwap is Linea and there is an official RPC for it, if it's Uniswap with ETH it should Infura (if you don't have, I can provide URL)
• missing proper error handling of the empty env for the RPC URLs
  websocket URL must start with ws:// or wss:// (got '') - example