Add Game of Life exercise

[Steffan153]

https://forum.exercism.org/t/conways-game-of-life-exercise/5509/10
http://forum.exercism.org/t/are-maintainers-open-to-new-exercise-contributions/10669/2

I'm no expert at F#, so the example solution can probably be improved :) It's just how I would solve it.

[github-actions]

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[ErikSchierboom]

Fab work! I've left some comments.

[ErikSchierboom]

Love it!

[ErikSchierboom]

Just one lint failure

[ErikSchierboom]

Fantastic!