Add created footer to App, improve app name

[iamandrewluca]

Type of issue: suggestion

Chapter: 8

If it's a suggestion:

Import created footer in src/shared/app.jsx

import Footer from './component/footer'

Add it after </Switch> statement or in other desired place.

<!-- ... -->
  <Route path={HELLO_ASYNC_PAGE_ROUTE} render={() => <HelloAsyncPage />} />
  <Route component={NotFoundPage} />
</Switch>
<Footer />

Also because we have {APP_NAME} in nav bar, remove

<h1>{APP_NAME}</h1>

in src/shared/app.jsx right before <Helmet titleTemplate... to make app look better!