Add support for `tailwind.prefix` config

[obedm503]

shadcn/ui supports setting a prefix in the config. This is especially useful when integrating tailwind in legacy projects.

This is what it looks like in the components.json:

{
  "tailwind": {
    "prefix": "tw-"
  }
}

My current workaround is to add the prefix to every component manually. Please add support for the tailwind prefix.