This PR updates the `cms-sanity` example to use:
- App Router
- TypeScript
- Sanity Studio v3 instead of v2
- Embeds the Studio inside the next app on the `/studio` route.
- ISR / Data Cache (revalidations through `revalidatePath` while in Live
Visual Editing, time-based to match the Sanity API CDN in production).
- Support Vercel Visual Editing out of the box.
- The new `next-sanity/image` component.
- Vercel Speed Insights.
- The Sanity Presentation Tool for live content previews.
- Sanity Portable Text setup to fully support `@tailwindcss/typography`.
- [AI Assist](https://www.sanity.io/docs/ai-assist)
- Auto fill in `alt` text on images.
- Preset prompts for content creation
41019c2314