Improved Flyweight example comments.

flyweight/src/main/java/com/iluwatar/PotionFactory.java

@@ -4,7 +4,10 @@ import java.util.EnumMap;
 
 /**
  * 
- * Flyweight.
+ * PotionFactory is the Flyweight in this example.
+ * It minimizes memory use by sharing object instances.
+ * It holds a map of potion instances and new potions
+ * are created only when none of the type already exists.
  * 
  */
 public class PotionFactory {
@@ -45,5 +48,4 @@ public class PotionFactory {
 		}
 		return potion;
 	}
-
 }