Restore vercel.jsons (#2650)

This PR restores the vercel.json files in the examples/dotcom
directories.

### Change Type

- [x] `internal` — Any other changes that don't affect the published
package[^2]

apps/docs/components/Footer.tsx

@@ -15,7 +15,7 @@ export function Footer() {
 						WebkitMask: `url(/tldraw-icon.svg) center 100% / 100% no-repeat`,
 					}}
 				/>
-				<p>tldraw © 2023</p>
+				<p>tldraw © 2024</p>
 			</a>
 			<div className="footer__socials">
 				<a