Unconver Image Game - Bug created by source formatting in banner update

[rtpHarry]

On this page:

https://www.learnrxjs.io/learn-rxjs/recipes/uncover-image-game

In this commit:

https://github.com/btroncone/learn-rxjs/commit/85908f6a5225afadad570474139cce60a62ea73b

The pluck code got corrupted by the source formatting tool that was applied:

https://github.com/btroncone/learn-rxjs/commit/85908f6a5225afadad570474139cce60a62ea73b#diff-b3c46e7d3a576a69c7c246c88a7f7d0d9b2cfc42847228e0d36f1daf21f6b5fcL170

It should be:

    pluck<KeyboardEvent, string>("code"),