title: How to set offset for the first element of UICollectionView
body: <p>I want to set offset offset for the first element of collectionView, so the first cell will apear in the center of the collectionView. <a href="https://i.stack.imgur.com/M25kw.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/M25kw.jpg" alt="See photo"></a></p>