See this commit: https://github.com/how-to-react/nwb-styleguidist/commit/e87da186cec7cf0e1e60b712e39f3016e2849467 for whats involved.
See this commit: https://github.com/how-to-react/nwb-styleguidist/commit/01bd8da0688dd513aee7bd6c95b25a31a6c88d0e
For adding sass, and a template for adding other missing loaders.