Add example for fetching a game detail view with cover art #6

Background

Many apps using IGDB need a game detail page that fetches a single game by slug or ID and renders summary, release date, rating, and cover art.

Proposed change

Add a copyable example file that uses the typed query builder to fetch one game and buildImageUrl() to build a cover image URL.

Acceptance criteria

• Uses .first() or .findById() accurately.
• Selects only fields needed by the detail view.
• Handles a missing game or missing cover image gracefully.
• Calls client.dispose() in a finally block like the existing examples.

Files likely involved

• examples/game-detail.ts
• examples/README.md
• docs/examples.md