docs(form): add regle example

[victorgarciaesgi]

❓ 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

Hi!

I'm the maintainer of Regle, a Vue headless validation library and "successor" of Vuelidate.

Vuelidate is not maintained anymore, and Regle is listed as the primary alternative as API is greatly similar.

This is also the recommended solution in Quasar https://quasar.dev/vue-components/field#external-validation

Regle also implements the Standard Schema spec, that means that it can be used with the Nuxt UI Form component.

This PR adds a working example of Regle usage in the Form component page 👍

Tests

Manual test as it's a documentation change

📝 Checklist

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

[pkg-pr-new]

npm i https://pkg.pr.new/@nuxt/ui@5178

commit: 0b2305b

[victorgarciaesgi]

@benjamincanac @romhml removed both @regle/core and @regle/rules from root. Updated lockfile