Update EIP-223: Update eip-223.md

[Dexaran]

Correct spelling.

Replace bytes32 symbol type with string because it must be string.

Add standard function to the ERC-223 standard description because it was removed as per this comment #6485 (comment)

This must be noted that "Interface introspection" and "Standard recognition" are two different tasks and therefore EIP-165 is not applicable to standard recognition.

interface HybridToken {
    function transfer(address to, uint256 value) external returns (bool);
    function approve(address spender, uint256 value) external returns (bool);
    function transferFrom(address from, address to, uint256 value) external returns (bool);
}

For example this hybrid token can utilize ERC-20 transferring patterns or ERC-223 transferring patterns depending on how it's transfer function is implemented.

Also, this is not a new method of introspection that I'm planning to introduce so there is no reason to submit it as a new EIP. This is just a method of identifying whether a token implements ERC-223 compatible transfer function or not for UIs.

[eth-bot]

✅ All reviewers have approved.

[eth-bot]

All Reviewers Have Approved; Performing Automatic Merge...