Credit original author of CHIP-8 games

[Tobias V. Langhoff]

The provided Chip-8 games are supplied from Zophar's Domain. Original author unknown.

The games in your repo were created by David Winter: https://www.pong-story.com/chip8/

Note that these games were made for Winter's own CHIP-8 interpreter, which in turn was based on CHIP-48, which contains many incompatibilities with other interpreters. If your emulator, and book, are based on that, it's probably incompatible with many games made both before and after the early 90s.