feat: auto install @nuxtjs/color-mode module

[selemondev]

Issue: #537

❓ 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

This pull request is intended to install the @nuxtjs/color-mode module alongside the installation of the shadcn-nuxt module. Why do so? Adding dark mode functionality has become a standard practice for many developers using Shadcn Vue in their web apps. To enhance developer experience (DX), it would be highly beneficial if the @nuxtjs/color-mode module were pre-installed and automatically configured.

Closes: #537

📝 Checklist

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

[Rednas83]

When this module is used with nuxt 3.14.0 I get
ERROR Cannot start nuxt: Nuxt module should be a function: @nuxtjs/color-mode

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- Operating System: Windows_NT
- Node Version:     v22.11.0
- Nuxt Version:     3.14.0
- CLI Version:      3.15.0
- Nitro Version:    2.10.2
- Package Manager:  [email protected]
- Builder:          -
- User Config:      default
- Runtime Modules:  normalizedModule(), normalizedModule(), @vueuse/[email protected], @nuxt/[email protected], @nuxt/[email protected], @nuxtjs/[email protected], @nuxt/[email protected], [email protected], [email protected], @nuxt/[email protected], @formkit/[email protected], @nuxt/[email protected]
- Build Modules:    -
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[xak2000]

Related to #864.