Hints for gourmand in main

Hints

• asv-content-rating-missing
  io.github.GourmandRecipeManager.Gourmand.appdata.xml -
  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/
• asv-developer-info-missing
  io.github.GourmandRecipeManager.Gourmand.appdata.xml -
  This component contains no `developer` element with information about its author.