Stuff got ugly so some more refactoring. I want rendering
completely independent from the game logic, i.e. so that
becomes a pure projection from the state (for some value of pure).
Also added the main game idea in the README and added a plan.
On my tuxedo laptop with a hosted guix on an Ubuntu derivative the
configure script found the host guile version which lead to loading
incompatible bytecode of the guix provided libraries. Updated the
README.
