Add an example env

[SonOfMosiah]

Would be helpful to have an example env file for running the tests during development.

[Andrey Petrov]

Good call, where's the best place to put it? .env.example?

Should be something like

export INFURA_API_KEY="..."
export ETHERSCAN_API_KEY="..."
export PROVIDER="ethers"  # or "viem"

[SonOfMosiah]

Yep. A .env.example would be good. You can add a small change to the Readme under the Development header that says to get started cp .env.example .env