Example of EIP-712

A full stack example of how to implement EIP-712 in an ethereum contract.

Useful material

1. https://apurbapokharel.medium.com/eip712-a-full-stack-example-e12185b03d54
2. https://soliditydeveloper.com/ecrecover
3. https://medium.com/metamask/eip712-is-coming-what-to-expect-and-how-to-use-it-bb92fd1a7a26
4. https://github.com/danfinlay/js-eth-personal-sign-examples