Restore Rubik's cube example

[fingolfin]

We used to have an example showing how to solve the Rubik's cube on the website. Maybe we should restore it or a variant? It was quite nice.

A copy of this can be seen here: https://www.math.rwth-aachen.de/homes/GAP/WWW2/Doc/Examples/rubik.html

But of course we also have it in our git history.

[he7d3r]

Alternatively, it is also available at
https://web.archive.org/web/20240224233843/https://www.gap-system.org/Doc/Examples/rubik.html