Hints for kruler in main

Hints

• asv-developer-name-tag-deprecated
  org.kde.kruler.appdata.xml:155 -
  The toplevel `developer_name` element is deprecated. Please use the `name` element in a `developer` block instead.
• asv-developer-info-missing
  org.kde.kruler.appdata.xml -
  This component contains no `developer` element with information about its author.
• screenshot-no-thumbnails
  No thumbnails have been generated for screenshot 'https://cdn.kde.org/screenshots/kruler/kruler.png'.
  This could mean that the original provided screenshot is too small to generate thumbnails from.