Add Craft CMS Next.js Starter

I'd like to add the official Craft CMS + Next.js starter project to the Awesome Next.js list.

This production-ready starter provides:

• Clean separation of frontend (Next.js) and backend (Craft CMS) code
• Integration with Craft CMS's built-in GraphQL API
• Blog, category feeds, and guestbook with clean pagination
• Live preview functionality with support for shareable draft URLs
• GraphQL mutations demonstrated through a guestbook example
• DDEV setup for streamlined local development

The starter is officially maintained by Pixel & Tonic, the makers of Craft CMS, and serves as an excellent starting point for developers looking to create headless applications with Next.js and Craft CMS.