Remove reference to Tooltip object.
Remove reference to Tooltip object.

The original game contained a tooltip to link to a search for Alan
Turing, but this release does not have that. I missed this while
preparing the original commit.

Codex-NG/turing-doodle,spirosrap/spirosrap-turing,Wagnerp/peterwagner-turing,Codex-NG/turing-doodle,spirosrap/spirosrap-turing,google/turing-doodle,iccor56/iccor56-tes,fieddinsum/turing-doodle,fieddinsum/turing-doodle,iccor56/iccor56-tes,Wagnerp/peterwagner-turing