title: How to download images async for WidgetKit
body: <p>I am developing Widgets for iOS and I really don't know how to download images for the widgets.</p>
  <p>The widget currently downloads an array of Objects, and every object has a URL of an image. The idea is that every object makes a <code>SimpleEntry</code> for the <code>Timeline</code>.</p>
  <p>What's the best way of achieving this? I read that Widgets shouldn't use the <code>ObservableObject</code>. I fetch the set of objects in the timeline provider, which seems to be what Apple recommends. But do I also download the images there and I wait until all are done to send the timeline?</p>
  <p>Any advice would be very helpful,</p>