[Sept Sprint] Chess Board

[iHiD]

This is part of our September Spring to get the Go Track in shape. Please read the Overview issue for more details. This exercise is claimed by @bobtfish.

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• chessboard: tweak introduction #1604
• chessboard: replace byte with int #1601
• chessboard: don't use type definitions #1603

[bobtfish]

Guess I'm claiming this one too 🤣