Merge pull request #490 from petrkle/related-applications-info

Add criteria for related app install banner

app-install-banner/related-applications/index.html

@@ -36,6 +36,8 @@ <h1>Web App Install Banner: Related Apps (Android currently) Sample</h1>
       <li>The site has a manifest declared</li>
       <li>The manifest has a <code>short_name</code>, 144 pixel icon and a type of 'image/png'</li>
       <li>The manifest has a <code>related_applications</code> section with an object that has the 'type': 'play' and a Google Play Store package ID.</li>
+      <li><a href="https://developers.google.com/web/fundamentals/security/csp/">Content Security Policy</a> allow load images from https://*.ggpht.com</li>
+      <li>Related application is not yet installed.</li>
     </ul>
 
     <p>To see if this example works, come back in another day and you will see the banner.</p>