Documentation: Update link-no-children error page for new link (vercel#46514)

The example still has an `<a>` inside the `<Link>` which was deprecated
with next 13.

Current page: https://nextjs.org/docs/messages/link-no-children

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## Documentation / Examples

- [x] Make sure the linting passes by running `pnpm build && pnpm lint`
- [x] The "examples guidelines" are followed from [our contributing
doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md)

---------

Co-authored-by: JJ Kasper <[email protected]>
Co-authored-by: Tim Neutkens <[email protected]>

Author: 3 people

errors/link-no-children.md

@@ -11,9 +11,11 @@ import Link from 'next/link'
 
 export default function Home() {
   return (
-    <Link href="/about"></Link>
-    // or
-    <Link href='/about' />
+    <>
+      <Link href="/about" legacyBehavior></Link>
+      // or
+      <Link href="/about" legacyBehavior />
+    </>
   )
 }
 ```
@@ -27,9 +29,13 @@ import Link from 'next/link'
 
 export default function Home() {
   return (
-    <Link href="/about">
-      <a>To About</a>
-    </Link>
+    <>
+      <Link href="/about">To About</Link>
+      // or
+      <Link href="/about" legacyBehavior>
+        <a>To About</a>
+      </Link>
+    </>
   )
 }
 ```