Snake game (homework): Discourage extending on the console

[encukou]

The Snake game from homeworks is turn-based, which isn't very fun (and it doesn't match the original game). Several people tried to extend it so it can be played in real-time, but this requires non-trivial hacks, and generally can't be solved by beginners. So, either:

• Explicitly discourage this; say that it'll only be possible after learning Pyglet
• Find an easy-to-use pip-installable library that does this
• Package the StackOverflow answers into an easy-to-use pip-installable library :)

The third option would work nicely as an individual project after the beginners' course; I'll try offering to mentor it.