Hints for nitrokey-app in ubuntu

Hints

• asv-developer-name-tag-deprecated
  :39 -
  The toplevel `developer_name` element is deprecated. Please use the `name` element in a `developer` block instead.
• asv-content-rating-missing
  -
  This component has no `content_rating` tag to provide age rating information. You can generate the tag data online by answering a few questions at https://hughsie.github.io/oars/
• screenshot-no-thumbnails
  No thumbnails have been generated for screenshot 'https://raw.githubusercontent.com/Nitrokey/nitrokey-app/master/images/icon/nitrokey-app-icon-128-black.png'.
  This could mean that the original provided screenshot is too small to generate thumbnails from.