docs(api): add <NuxtWelcome /> component docs

[umutiq]

🔗 Linked issue

resolvesnuxt/nuxt#14613

❓ 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

Solves nuxt/nuxt#14613

📝 Checklist

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

[netlify]

✅ Deploy Preview for nuxt3-docs ready!

Name	Link
🔨 Latest commit	f7f4a11
🔍 Latest deploy log	https://app.netlify.com/sites/nuxt3-docs/deploys/62fe44bb2ae04e00087ae695
😎 Deploy Preview	https://deploy-preview-6745--nuxt3-docs.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site settings.

[pi0]

Do you mind to add a ::ReadMore link to https://github.com/nuxt/ui?

[umutiq]

@pi0 Since we didn't mention it's imported from @nuxt/ui, i think it's inapporpriate.

[danielroe]

Maybe we should mention it then. I think it would be a good idea for people to know where (for example) to make PRs if they have improvements.

[umutiq]

@danielroe I added alert and Readmore links to document. Can you check it?

[pi0]

Thanks <3

[BD103]

Thank you!