Ensure the generated composable name is properly formatted

[franklin-tina]

🔗 Linked issue

❓ 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

The current implementation assumes users will run the command to generate a composable as follows:

1. prefixed with use
   nuxi add composable useSomeComposable

// useSomeComposable.ts
export const useSomeComposable = () => {
  return ref()
}

2. without use prefix
   nuxi add composable someComposable

// someComposable.ts
export const useSomeComposable = () => {
  return ref()
}

However, if the user runs these commands with the names in kebab case, the resulting function will be broken:

1. prefixed with use
   nuxi add composable use-some-composable

// use-some-composable.ts
export const use-some-composable = () => {
  return ref()
}

2. without use prefix
   nuxi add composable some-composable

// some-composable.ts
export const useSome-composable = () => {
  return ref()
}

This PR ensures the resulting composable function is properly formatted, regardless of whether or not the user uses kebab case or camelCase in their composable definition:

use-some-composable → useSomeComposable
good → useGood
someGoodComposable → useSomeGoodComposable
usegood-composable → useGoodComposable

[danielroe]

thank you ❤️