Add weapon data

public/data/weapons/gyukikiri-nagamitsu.json

@@ -0,0 +1,17 @@
+{
+  "id": "gyukikiri-nagamitsu",
+  "name": "Gyukikiri Nagamitsu",
+  "atk": 289,
+  "crt": 17,
+  "rarity": 5,
+  "skills": [
+    {
+      "name": "Kageryuu Blade Art",
+      "description": "Starts charging energy when sprinting. When the duration of the sprint reaches 0.5s, 1.5s, and 3s, the following Sprint Attack generates an explosion centered on the first enemy hit, dealing 400%, 600%, and 800% ATK of Physical DMG respectively."
+    },
+    {
+      "name": "Sharp Edge",
+      "description": "When Combo Hit Count is 5 or less, gain 32.0% Physical DMG."
+    }
+  ]
+}