nestInSelector = (
      /** @type {string} */ content,
      /** @type {string} */ selector,
      /** @type {string} */ indentation,
    ) => {
      return `${indentation}${selector} {\n` + content + `\n${indentation}}`;
    }
Creates a CSS file with variable definitions based on the style dictionary

@memberof Formats
@kind member

@example
```css
:root {
  --color-background-base: #f0f0f0;
  --color-background-alt: #eeeeee;
}
```