feat: add sevalla preset

[olawanlejoel]

🔗 Linked issue

❓ Type of change

• [x] 📖 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)
• [x] ✨ 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

Sevalla is a modern cloud platform for hosting applications, databases, object storage and static sites, offering a simple and scalable deployment experience.

This PR introduces a new preset named sevalla, allowing users to easily deploy their Nitro apps to Sevalla with Node server support. The preset ensures compatibility and provides a straightforward deployment workflow.

Additionally, the documentation has been updated with a dedicated Sevalla deployment guide, making it easy for users to get started and configure their environment.

📝 Checklist

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

[vercel[bot]]

@olawanlejoel is attempting to deploy a commit to the Nitro Team on Vercel.

A member of the Team first needs to authorize it.

[pi0]

@olawanlejoel feel free to join Nitro discord if you like to followup over chat.

[olawanlejoel]

Hi @pi0, I attended to the comments you raised