message: Slid scene into view, making animation clearer
diff: ReactDOM.render(
  <NavigationReactMobile.NavigationMotion
  startStateKey="people"
  - unmountedStyle={{opacity: 0}}
  - mountedStyle={{opacity: 1}}
  - crumbStyle={{opacity: 0}}
  + unmountedStyle={{opacity: 1, translate: 1}}
  + mountedStyle={{opacity: 1, translate: 0}}
  + crumbStyle={{opacity: 0, translate: 0}}
  stateNavigator={stateNavigator}>
  - {({opacity}, scene, url) => (
  + {({opacity, translate}, scene, url) => (
  <div key={url}
  style={{
  position: 'absolute',
  opacity,
  + transform: `translate(${translate * window.innerWidth}px)`,
  + opacity,
  left: 0,
  right: 0,
  top: 0,
  