Update legacy.md

[Mirmuxsin]

This pull request...

• [ ] Closes #TICKET-NUMBER

Checklist:

• [ ] I have opened the issue ticket that this pull request is part of.
• [ ] This pull request title contains (#TICKET-NUMBER) for reference.
• [ ] This pull request description contains Closes #{$ISSUE_NO} that closes ticket.
• [ ] This pull request is all my own work - I have not plagiarized.
• [ ] This contribution is licensed under MIT or compatible license.
• [ ] All code is covered in unit tests and all tests pass.
• [ ] I have updated the docs to cover my changes (if applicable).
• [ ] All function parameters and return values are annotated with PHP type hints.
• [ ] All functions have PHPDocs blocks.