game.validate-move will now return an error code is the move is invalid.
default error messages are found in lib/constants.fnl. error handling is
now handled on the front end.
- isolate core game logic and move it to src/game.fnl
- main.fnl should be just the ui now
- move all table funcs into lib/table
- move all (1) string funcs into lib/string
- move all game funcs into lib/game/