Changes made for this site (original: https://github.com/Quinten/black-hole-square @ 4a760a0f3d182c833e345937a0fe4b7704afd737)
- Copied the prebuilt public/index.html (webpack output committed by the author) and public/icon.png, plus LICENSE.
  The unminified source is in the src/ folder of the repository linked above.
- index.html: removed the <meta name="monetization"> Web Monetization payment-pointer tag.
- index.html: removed the service-worker registration call (public/sw.js is not copied) and the web app manifest
  link (public/manifest.json is not copied).
No game logic was changed. In this commit the author had already removed the monetization lock, so all 18 puzzles,
including the three former bonus puzzles, are playable.