Moved component locations should be marked as breaking changes

When upgrading to the beta I got this error:

./docs_helpers/DocsWrapper.js
Module not found: Can't resolve 'react-styleguidist/lib/rsg-components/StyleGuide/StyleGuideRenderer'

When I change the path to react-styleguidist/lib/client/rgs-components... it compiled.

Since these module locations have been treated as public API (for overrides), their change in location should be documented as a breaking change.