Update to Design.md to correct code for API code reference

[bradical1379]

Description of the Change

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How to test the Change

Changelog Entry

Added - New feature Changed - Existing functionality Deprecated - Soon-to-be removed feature Removed - Feature Fixed - Bug fix Security - Vulnerability Developer - Non-functional update

Credits

Props @username, @username2, ...

Checklist:

• [ ] I agree to follow this project's Code of Conduct.
• [ ] I have updated the documentation accordingly.
• [ ] I have added Critical Flows, Test Cases, and/or End-to-End Tests to cover my change.
• [ ] All new and existing tests pass.