doc: update nextjs page router tutorial code for the latest create-t3 (#336)

* doc: update nextjs page router tutorial code for the latest create-t3

* add session provider setup

* grammar change

Author: jiashengguo

docs/quick-start/nextjs-app-router.mdx

@@ -101,6 +101,11 @@ npx zenstack generate && npx prisma db push
 
 ### 4. Configure NextAuth to use credential-based auth
 
+First, we need to install type definitions for bcryptjs
+```bash
+npm install --save @types/bcryptjs
+```
+
 Now let's update `/src/server/auth.ts` to the content below to
 use credentials auth and JWT-based session: