Added experience system

dungeonbattle/entities/player.py

@@ -3,3 +3,15 @@ from ..interfaces import FightingEntity
 class Player(FightingEntity):
     maxhealth = 20
     strength = 5
+
+    currentXP: int
+    maxXP: int
+
+    def level_up(self):
+        if currentXP>maxXP :
+            self.level+=1
+            currentXP = 0
+            maxXP = self.level*10
+    def addXP(self, xp) :
+        currentXP+=xp
+        self.level_up()