chore(ci): add GitHub PR template

[shinGangan]

🔗 Linked issue

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

GitHub PR template for Nuxt UI has been added.
I also plan to organize the necessary Issue templates and create a separate PR.

[vercel]

@shinGangan is attempting to deploy a commit to the Nuxt Team on Vercel.

A member of the Team first needs to authorize it.

[shinGangan]

This PR has low priority for review, so if there is something else that is a priority, please prioritize it first. 🙏

[harlan-zw]

Great, thanks :)