PaperGames - Snakes and Ladders (embedded copy)

Original project: PaperGames by Christopher Müller
Repository: https://github.com/YourChaosChris/PaperGames
Commit: 61e6a1ec8a0cd649cd9196af4f5def83e541706e
License: MIT (see LICENSE). NOTICE and README.md are copied unchanged; README.md holds the
"Third-party assets" section that NOTICE refers to. None of the third-party assets listed there
(chess piece set, xiangqi/shogi piece drawings, game-icons.net home-page icons) are used by this
game or included in this folder.

What was copied: only the files that snakesladders.html loads - snakesladders-core.js, snakesladders-app.js,
style.css and the shared helper scripts listed in index.html. snakesladders.html was renamed to index.html.
Not copied: every other game, the rules/history pages, the lang/ translation files, sw.js,
manifest and icons.

Changes:
1. index.html (was snakesladders.html)
   - <head> rebuilt: removed the canonical-link script, the hreflang alternate links, the Open Graph
     and Twitter meta tags (all pointing at yourchaoschris.github.io), the favicon, apple-touch-icon,
     manifest and theme-color links, and the inline language-detection script. The <title> is now
     "Snakes and Ladders | PaperGames"; the meta description is kept.
   - <html> gets data-game="snakesladders" so quick-rules.js still finds this game's short rules.
   - The header "PaperGames" home link and the "by Christopher Müller" about link are now plain
     text (the credit itself is kept).
   - Removed the footer links to the original site's legal notice and privacy policy pages.
   - Removed these script tags: sw-register.js (service worker registration), update-banner.js,
     force-update.js and offline-status.js (service-worker/offline-cache features), game-switcher.js
     (drop-down and "Related games" links to the app's other games) and rules-link.js (link to a
     separate rules page that is not included).
2. i18n.js: getLang() always returns English, because the lang/*.js translation files are not
   shipped. One English string (home_four_in_a_row_desc) was reworded to avoid a trademarked name.
3. settings-menu.js: removed the Language section and the Version / "Force update now" section.
4. quick-rules.js: reads the game id from <html data-game> instead of the file name; removed the
   "All rules" link to the separate rules page.
5. game-storage.js, game-stats.js: emptied the old-name migration maps (they only listed former
   page names, two of them trademarked game names).
6. style.css: a trademarked game name in code
   comments was replaced with "four-in-a-row". Comments only.

The game rules, computer opponents, board drawing and layout are unchanged. Text files were
kept with their original CRLF line endings.