Hints for redshift in main

Warnings

• ancient-metadata
  The AppStream metadata should be updated to follow a more recent version of the specification.
  Please consult the MetaInfo quickstart guides for more information.
• screenshot-download-error
  Error while downloading screenshot from 'http://jonls.dk/assets/screenshot1.png': URL was not found on the server.
  This might be a temporary server issue, or the screenshot is no longer available.