chore: add single-file multi-theme example

[jorenbroekema]

Verify example with dependencies:

"@tokens-studio/sd-transforms": "^1.2.9",
"style-dictionary": "^4.2.0"

and this tokenset:

{
  "core/colors": {
    "colors": {
      "red": {
        "value": "#f00",
        "type": "color"
      }
    }
  },
  "core/dimensions": {
    "spacing": {
      "5": {
        "value": "20px",
        "type": "dimension"
      }
    }
  },
  "$themes": [
    {
      "id": "6be618dc1cae3215f1793c74e72f3095e4de3527",
      "name": "Light",
      "group": "Theme",
      "selectedTokenSets": {
        "core/colors": "enabled"
      }
    },
    {
      "id": "28983d638284cad3d6ad7965ac4046e1f48f6588",
      "name": "Dark",
      "group": "Theme",
      "selectedTokenSets": {
        "core/dimensions": "enabled"
      }
    }
  ]
}

The output should be that you get a tokens folder with 2 files (core/colors.json and core/dimensions.json) each with their respective tokens contents, as well as an output of vars-Dark.css -> dimensions content and vars-Light.css -> colors content

[changeset-bot]

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Latest commit: 2493fd6

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