Additional comment

+ Added additional comment explaining what DELTA is.

cockatrice/src/carditem.h

@@ -14,6 +14,7 @@ class QColor;
 const int MAX_COUNTERS_ON_CARD = 999;
 const float CARD_WIDTH_HALF = CARD_WIDTH / 2;
 const float CARD_HEIGHT_HALF = CARD_HEIGHT / 2;
+// DELTA is the degrees of rotation that will animate between frames
 const int DELTA = 10;
 
 class CardItem : public AbstractCardItem {