feat: add myjson.online driver

[justboereh]

🔗 Linked issue

#325

❓ Type of change

• 📖 Documentation (updates to the documentation, readme, or JSdoc annotations)
• 🐞 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)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

📝 Checklist

This PR adds the myJson driver requested by issue #325. Also added basic documentation.

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

[nuxt-studio]

✅ Live Preview ready!

Name	Edit	Preview	Latest Commit
unstorage	Edit on Studio ↗︎	View Live Preview	beab2d3

[itpropro]

Thanks a lot for your driver!
I am not really sure if we need an additional driver for this service, as there already is the general http driver. Is there any limitation that prevented you from using the http driver with custom TransactionOptions for headers using the opts parameter?