Fix file path to posts detail page (#7574)

Author: FabianVolkers

apps/docs/content/docs/guides/frameworks/nextjs.mdx

@@ -428,7 +428,7 @@ In the `posts` directory, create a new `[id]` directory and a new `page.tsx` fil
 mkdir -p "app/posts/[id]" && touch "app/posts/[id]/page.tsx"
 ```
 
-This page will display a single post's title, content, and author. Just like your other pages, add the following code to the `app/posts/new/page.tsx` file:
+This page will display a single post's title, content, and author. Just like your other pages, add the following code to the `app/posts/[id]/page.tsx` file:
 
 ```tsx title="app/posts/[id]/page.tsx"
 import prisma from "@/lib/prisma";