Update EIP-3074: Explain `nonce` and `chainId` better

[SamWilsn]

[eth-bot]

✅ All reviewers have approved.

[sambacha]

shouldnt this be in the security considerations section regarding chainId?

[github-actions[bot]]

There has been no activity on this pull request for 2 weeks. It will be closed after 3 months of inactivity. If you would like to move this PR forward, please respond to any outstanding feedback or add a comment indicating that you have addressed all required feedback and are ready for a review.

[github-actions[bot]]

This pull request was closed due to inactivity. If you are still pursuing it, feel free to reopen it and respond to any feedback or request a review in a comment.