Deck object: Better handling for orphaned items

The article landing page (`/thinks`) has 11 posts on it. On large screens this works great, but on medium screens the number of posts leads to odd rows:


Making cards horizontal at this size could fix it, but looks too squished:


We could investigate better ways to handle this, though it may be resolved when we handle https://github.com/cloudfour/cloudfour.com-wp/issues/612