fix(i18n): support excluded locales

[Xenossolitarius]

🔗 Linked issue

#330

❓ 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

Takes in account excluded locales so the users don't create empty sitemaps

[vercel]

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

A member of the Team first needs to authorize it.

[harlan-zw]

Thank you, I was not aware of this feature. Sorry for the delay