leave some documentation on Zone classes (#5199)

* leave some documentation on Zone classes

* small refactor

* undo functional change from refactor and clean up comments

* move variables into if block

cockatrice/src/game/board/abstract_graphics_item.h

@@ -13,6 +13,9 @@ enum GraphicsItemType
     typeOther = QGraphicsItem::UserType + 6
 };
 
+/**
+ * Parent class of all objects that appear in a game.
+ */
 class AbstractGraphicsItem : public QObject, public QGraphicsItem
 {
     Q_OBJECT