Add EIP: Minimal Multi-Token Interface

[jtriley-eth]

When opening a pull request to submit a new EIP, please use the suggested template: https://github.com/ethereum/EIPs/blob/master/eip-template.md

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[eth-bot]

✅ All reviewers have approved.

[github-actions]

The commit c9292dc (as a parent of 7fcc789) contains errors.
Please inspect the Run Summary for details.

[SamWilsn]

I think you'll need to expand the title a bit. Multi-token doesn't give the reader enough information about the proposal.

[jtriley-eth]

expanded to "Minimal Multi-Token Interface"

[eth-bot]

All Reviewers Have Approved; Performing Automatic Merge...