Add a deliberately broken level (#81)

Made a copy of the main scene that has some significant bugs in it. This
is for exploring QA and Playtesting in Explore: Threadbare.

The deep link functionality from #80 will be used to give learners a
link directly to this scene. It is not otherwise accessible in-game.

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Co-authored-by: Will Thompson <wjt@endlessaccess.org>

Author: jgbourque