Update src/content/docs/en/guides/upgrade-to/v6.mdx

Co-authored-by: Sarah Rainsberger <[email protected]>

src/content/docs/en/guides/upgrade-to/v6.mdx

@@ -137,7 +137,7 @@ Notably, many `string()` formats have been deprecated (e.g. `z.string().email()`
   }
   ```
 
-You can import Zod from `astro/zod` to ensure you're using the same version of Zod that Astro uses internally:
+You can ensure you're the same version of Zod that Astro uses internally by [importing Zod from `astro/zod`](#deprecated-astroschema-and-z-from-astrocontent).
 
 ```ts
 import { z } from 'astro/zod';