* Propose Multi-Resource Token standard

RMRK team has developed a next step in NFTs where one NFT can be tied to
multiple resources.

* Address issues reported by EIP repository's CI

* Fix styling discrepancies in section titles

* Address CI's issues in the preabmle

* Add discussion URL

* Fix discussion URL formatting

* Add the EIP number

* Fix getResourceMeta specification

* Apply changes based on PR comments

* Replace "primitive" with a clearer explanation

Co-authored-by: Pandapip1 <[email protected]>

* Apply changes based on ECH call #5

Applied the changes based on feedback received on the EIP Editing Office
Hour Meeting #5.

This commit includes changes to the proposal as well as adds an exaple
implementation to assets/ directory.

* Address the stylistic issues reported by the CI

* Fix a reference to EIP-712

* Minor typo fixes

* Updates `getResourceMetadata` description

Co-authored-by: Sam Wilson <[email protected]>

* Rename MultiResource -> MultiAsset and relicense

The proposal was renamed to Context-Dependent Multi-Asset Tokens to
better illustrate its function.

Another example was added to represent the possible IoT usecase and the
explanation on the naming decision was added to the rationale.

The examples were relicensed to CC0, to conform to the requirements of
EIP repository.

* Fix license identifier & Specification contract title

* Fix indexes of Rationale questions

* Minor polishing of the rationale

* Update references to assets to use an istead of a in Rationale

* Final polishes

Co-authored-by: Pandapip1 <[email protected]>
Co-authored-by: Steven Pineda <[email protected]>
Co-authored-by: Sam Wilson <[email protected]>

* EIP Motivation and Specification for "Multi-operator, per-token ERC721 approval."

* Add remaining authors' names

* Interface overhaul with explanation in EIP markdown.

* Add `Abstract` and `@dev` note about interplay with `setApprovalForAll()`.

* Partial response to cxkoda review

* Full response to cxkoda review

* Explicitly include OZ `IERC{165,721}.sol` instead of using a submodule

* Minor typo and wording changes to draft.

* Prune authors to active participants as they can always be re-added later

* Revert `.gitignore` so as to not change it in the EIP draft (#7)

* Set presumptive EIP number and fix linter complaints (#5)

* Rename files and directories to include EIP number

* Address linter (`EIP Walidator`) issues

* Add presumed EIP number based on PR: 6464

* Revert `.gitignore` to get through initial draft acceptance

* Do the last commit properly ;)

* Add ERC category

* Fix linter issues (#8)

* Update EIP- references to ERC-

* Remove OpenZeppelin interfaces and replace with original EIP versions; change 6464 license to CC0

* Add `solidity` language tag to code block