Reis naar Mars

A dice game over the weeks of a trip to Mars, for the space theme (groep
7-8). Each week the pupil rolls for an event, puts the four astronauts on
the greenhouse (oxygen), repairs (against meteors) or navigation (an extra
step), and picks a speed: economy or full speed, which burns more fuel. The
log on the answer sheet holds the roll, the crew, the speed, and the
distance, oxygen and fuel after the week. The point is planning with three
quantities that pull against each other: going fast costs fuel, a big crew
in the greenhouse makes oxygen but doesn't get you there.

It is a game plugin (docs/game-plugins.md), like `tempono/hunter-gatherers`:
no key, the log is checked row by row, and the board (tracks for distance,
oxygen and fuel, spaces for the crew) prints in the booklet. Add a few
example weeks as `solution` for the teacher manual.