fix: Update enginegame.js to use the correct path for stockfish.js in the worker initialization.

[Elizura]

Fix: Correct fallback Stockfish engine path

The example hangs indefinitely while loading the engine because the fallback path is incorrect.

It currently points to:

src/stockfish.js

However, stockfish.js actually lives at:

node_modules/stockfish/bin/stockfish.js

Updating the path fixed the issue for me, and the example ran as expected.

I’ve also seen other issues reporting a similar loading problem (linked below), which this may resolve.

#105
#12