Add Base Sepolia testnet

[actuallymentor]

Hello team!

Could you please add the Base Sepolia testnet? These are the official base docs from which the testnet rpc data is:

Name	Sepolia
Network Name	Base Sepolia
RPC Endpoint	https://sepolia.base.org/
Chain ID	84532
Currency Symbol	ETH
Block Explorer	https://sepolia-explorer.base.org/

If you are overwhelmed and would appreciate a PR please point me in the right direction and I'll make one.