Rename game.html to index.html for GitHub Pages

- Rename game.html to index.html for cleaner URLs
- Update README.md and CLAUDE.md documentation
- Game now accessible at root URL without filename

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jamiely

CLAUDE.md

@@ -14,7 +14,7 @@ clojure -P
 
 # Start development server with hot reloading
 npx shadow-cljs watch app
-# Game accessible at http://localhost:8080/game.html
+# Game accessible at http://localhost:8080/
 
 # Compile for production (advanced compilation)
 npx shadow-cljs release app

README.md

@@ -14,7 +14,7 @@ A game to practice clojure and clojurescript. Only works in Chrome.
 
     # Start development server with hot reloading
     npx shadow-cljs watch app
-    # Navigate to: http://localhost:8080/game.html
+    # Navigate to: http://localhost:8080/
 
 ## Tests