Integration with Storybook and custom styles
This is a feature request.

It seems that now `react-sketchapp` could only be used only when all styles are inlined in JSX. This significantly limits its applicability for existing projects that often have separate CSS/SASS/LESS/PostCSS stylesheets and/or use something like Bootstrap.

What if there will be some tool that can parse existing demo site (including ones built with [Storybook](https://github.com/storybooks/storybook)), grab all actual [computed styles](https://developer.mozilla.org/en-US/docs/Web/API/Window/getComputedStyle) from DOM (which means app has to be truly rendered by a headless browser or similar) and then produce a temporary `react-sketchapp` app which in turn can be converted to Sketch file.

Sounds monstrous but should be quite viable.