Updating broken link to middleware docs for NextJS (#407)

Lint is failing for the project because the link to middleware
documentation for NextJS has changed with the latest version. Updating
the link to reference the current documentation on the NextJS website.

Author: JoeOakhartNava

template/docs/decisions/{{app_name}}/0006-use-nextjs.md

@@ -70,7 +70,7 @@ Next.js is maintained by Vercel, a PaaS for front-end hosting company.
   - Easy to learn and use with good documentation
   - [Strong Storybook support](https://storybook.js.org/recipes/next)
   - Often one of the first to adopt new React features (e.g. Server Components, Suspense) due to their close collaboration with the React team.
-  - Supports [internationalized routing](https://nextjs.org/docs/pages/building-your-application/routing/internationalization), [middleware](https://nextjs.org/docs/pages/building-your-application/routing/middleware), and there are [community-maintained auth libraries](https://next-auth.js.org/).
+  - Supports [internationalized routing](https://nextjs.org/docs/pages/building-your-application/routing/internationalization), [middleware](https://nextjs.org/docs/app/api-reference/file-conventions/middleware), and there are [community-maintained auth libraries](https://next-auth.js.org/).
 - **Cons**
   - Very opinionated with routing which can significantly increase code complexity for non-standard routes