Add ability to choose between using CSS variables or Tailwind CSS utility classes for theming

[MarvinZein]

Describe the feature in detail (code, mocks, or screenshots encouraged)

Like in the official shadcn/ui, the option for the components to be generated using tailwind utility classes instead of css variables should be added.

{
  "tailwind": {
    "cssVariables": `true` | `false`
  }
}

What type of pull request would this be?

New Feature

Provide relevant links or additional information.

https://ui.shadcn.com/docs/components-json#tailwindcssvariables

[FarhanAliRaza]

Can i help?