docs: fix incorrect TS types import path in documentation

[ViliusP]

🔗 Linked issue

#2349

❓ 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 like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Resolves #2349

Currently, to import the type, you need to specify '@nuxt/content', but the documentation states it should be '@nuxt/content/dist/runtime/types'.

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[farnabaz]

Thanks