Add weapon data

public/data/weapons/onyx-iron.json

@@ -0,0 +1,17 @@
+{
+  "id": "onyx-iron",
+  "name": "Onyx Iron",
+  "atk": 249,
+  "crt": 27,
+  "rarity": 5,
+  "skills": [
+    {
+      "name": "Protective Field",
+      "description": "[SP: 5][CD: 20s] Creates a shield that absorbs 12% Max HP of wielder when hit by enemy attack. While the shield stands, wielder heals 22.0 HP/s and ATKs gain 10.0% Total DMG Multiplier and deal 10% more Physical DMG. Duration: 10s."
+    },
+    {
+      "name": "Vitality Drive",
+      "description": "Gains a 1.20% Total DMG Multiplier and 0.50% Physical DMG buff per 10% HP that the wielder has."
+    }
+  ]
+}