Re: Entry page example with links to WAM/RWPM

I've adapted another example as well:
https://hadriengardeur.github.io/webpub-manifest/examples/MobyDick/

There are a few differences compared to the previous example:

   - no cross origin issues, which means that the basic viewer can easily
   handle caching through a Service Worker and track the location of the
   iframe (useful for the reading order)
   - both links to WAM and RWPM use rel=manifest but browsers only use the
   first one (WAM)
   - the RWPM is referenced in every resource from the publication
   (discovery on any resource vs entry page only)
   - the WAM contains icons (go to the entry page, then add it to
   homescreen on Android)
   - "standalone" is used as the display-mode in the WAM, to showcase the
   difference in behaviour
   - on the last page, if you click on go back to title, you can test the
   behaviour for out of scope resources (it opens a new webview)
   - the media query on the "standalone" display mode doesn't seem to be
   working for me (latest version of Android and Chrome)