feat: Create basic Ping Pong game

[neowick45]

Adds a fully playable 2D Ping Pong game with the following features:

• HTML structure (index.html) with a game canvas and instruction area.
• CSS styling (style.css) for the game elements and layout.
• JavaScript logic (script.js) implementing:
  • Player paddle controlled by mouse.
  • Simple AI for the opponent paddle.
  • Ball movement and physics (collision with walls and paddles).
  • Scoring system.
  • Ball reset after each point.
  • First player to 5 points wins the game.
  • Game over message and instructions to refresh for a new game.
• Instructions on how to play are included on the page.