Testing criteria:

1. Save article in a Featured article widget / Continue reading
2. Go back to the app and confirm that the featured article was saved

1. Go to Explore feed settings
2. Turn off 1 type of cards
3. Confirm that the cards don't appear in the feed

1. In Explore feed, tap on the ellipsis to customize a card
2. Choose to hide that card
3. Confirm that card collapsed
4. Leave Explore feed and go to a different view (for example, Saved)
5. Go back to the feed and confirm that the card's gone

1. In Explore feed, tap on the ellipsis to customize a card
2. Choose to hide all cards of that type
3. Confirm that card collapsed
4. Tap "Undo" on the collapsed card
5. Confirm that the card and all other cards of that type reappear in the feed
6. Leave Explore feed and go to a different view (for example, Saved)
7. Go back to the feed and confirm that all cards of that type are gone
8. Go to Explore feed settings and confirm that the switch for the toggled card type is off

1. In Explore feed, save a featured article by tapping on "Save for later" on the Featured article card
2. Confirm that the image doesn't flicker

+ other exploratory testing around loading and interacting with feed content