docs(getting-started): add "Getting Started Using AI" section

[bedus-creation]

Adds a new ## Getting Started Using AI section to docs/getting-started.md, mirroring Laravel's AI onboarding flow.

What changed

• A single copy-paste prompt that lets an AI coding agent (Claude Code, Cursor, Copilot, Windsurf, etc.) scaffold a structured, provider-driven Fastapi Startkit project from an empty directory.
• The prompt uses the recommended structured layout (artisan, bootstrap/application.py, config/, app/), uv for dependency management, and FastAPIProvider, then verifies the boot with uv run python artisan serve.
• Placed directly after the intro, before ## Prerequisites, so the manual steps below remain the fallback for hand setup.

Scope

• Edits docs/getting-started.md only.
• No new files; .vitepress/config.mts and the sidebar are untouched.

[bedus-creation]

Code Review verdict: APPROVE (posting as a comment — GitHub blocks formal self-approval since the authenticated account authored this PR).

Verified every technical claim in the prompt against the framework source:

• FastAPIProvider is exported from fastapi_startkit.fastapi (fastapi/init.py); registering it alone is valid and matches the doc's own Way 2 / Option B example.
• app.handle_command() exists (application.py:224) and matches the real application/artisan template.
• uv run python artisan serve works — ServeCommand (name "serve") is auto-registered by FastAPIProvider.boot().
• The fastapi-startkit[fastapi] extra exists in pyproject.toml.
• Python 3.12+ and the artisan/bootstrap/application.py/config//app/ layout match the existing guide verbatim.

Markdown is well-formed, the Claude Code link is correct, and the section is consistently styled with the rest of the file. No correctness, consistency, or accuracy issues found. Recommend merge.