docs: upgrade from 15 to 16 (#85176)

Co-authored-by: Ismael <[email protected]>
Co-authored-by: Jiachi Liu <[email protected]>

Author: 3 people

docs/01-app/01-getting-started/18-upgrading.mdx

@@ -5,6 +5,7 @@ related:
   title: Version guides
   description: See the version guides for in-depth upgrade instructions.
   links:
+    - app/guides/upgrading/version-16
     - app/guides/upgrading/version-15
     - app/guides/upgrading/version-14
 ---