message: Created history in stateNavigator constructor
  It's clearer and works with NavigationStack.HistoryManager check - because this is undefined on native so falls back to default history manager. Wanted to simplify for the documentation
diff: @@ -15,21 +15,16 @@ export default () => {
  {key: 'notifications', route: 'x/y'},
  {key: 'tweet', route: 'tweet/{id}', trackCrumbTrail: true, defaultTypes: {id: 'number'}},
  {key: 'timeline', route: 'timeline/{id}', trackCrumbTrail: true, defaultTypes: {id: 'number'}}
  - ]);
  -
  - if (Platform.OS === 'web') {
  - const buildStartUrl = url => {
  + ], NavigationStack.HistoryManager && new NavigationStack.HistoryManager(url => {
  const {state, data} = stateNavigator.parseLink(url);
  let fluent = stateNavigator.fluent().navigate('home');
  if (state.key === 'home' && data.tab === 'notifications')
  stateNavigator.historyManager.addHistory(fluent.url, true);
  return fluent.navigate(state.key, data).url;
  - };
  - stateNavigator.configure(stateNavigator, new NavigationStack.HistoryManager(buildStartUrl));
  - stateNavigator.start();
  - } else {
  - stateNavigator.navigate('home');
  - }
  + }));
  +
  + if (Platform.OS === 'web') stateNavigator.start();
  + else stateNavigator.navigate('home');
  const {home, notifications, tweet, timeline} = stateNavigator.states;
  const HomeLayout = Platform.OS === 'ios' ? Home : Tabs;
  