Add rarity to set

public/data/honkai3rd/stigmata-sets/mendeleev.json

@@ -9,5 +9,6 @@
   "threeSetSkill": {
     "name": "Element Prediction 3 Pieces",
     "description": "When Basic ATKs hit the enemy, enter Discovery State. Discovery State: Host gains Ignore Interrupt and deals 20.0% more Physical DMG. Discovery State ends and enters a 15s CD when Combo Hit chain is disrupted."
-  }
-}
+  },
+  "rarity": 5
+}