Update unread counts when returning to home

Reader/Screens/Home/HomeViewController.swift

@@ -79,6 +79,11 @@ class HomeViewController: UIViewController {
                 collectionView.deselectItem(at: indexPath, animated: true)
             }
         }
+        
+        var snapshot = dataSource.snapshot()
+        // reconfigure so that unread counts update
+        snapshot.reconfigureItems(snapshot.itemIdentifiers)
+        dataSource.apply(snapshot)
     }
     
     private func createDataSource() -> UICollectionViewDiffableDataSource<Section, Item> {