message: remove theme from index
diff: export {default as ExampleHeading} from './ExampleHeading'
  export {default as Header} from './Header'
  export {default as SideNav} from './SideNav'
  -export {default as customTheme} from './theme'
  export {default as IndexHero} from './IndexHero'
  export {default as BoxShadow} from './BoxShadow'
  export {default as PropsList} from './PropsList'
  