Add weapon data

public/data/weapons/tranquil-rhapsody.json

@@ -0,0 +1,21 @@
+{
+  "id": "tranquil-rhapsody",
+  "name": "Tranquil Rhapsody",
+  "atk": 415,
+  "crt": 35,
+  "rarity": 6,
+  "skills": [
+    {
+      "name": "Night Phantom",
+      "description": "[SP: 0][CD: 20s] Hold the weapon active button to enter Nightwalk mode (last 2s), during which the wielder is immune to attack; release the button to make wielder reappear and leap backwards pulling in enemies around her and dealing 1000% ATK of AOE Ice DMG. If wielded by Sixth Serenade, she will gain 300 points of Nachtsicht upon entering Nightwalk mode; in Nightwalk mode, she gains another 300 points of Nachtsicht (once during each skill span) and deals 200% ATK of Ice DMG when passing through an enemy; after casting the weapon active, tap [ATK] to immediately unleash her Combo ATK at no Nachtsicht cost."
+    },
+    {
+      "name": "Dirge of Totenmond",
+      "description": "After unleashing the weapon active or Ultimate, the wielder deals 40.0% more Total DMG for 9s; CD: 15."
+    },
+    {
+      "name": "Frost Raven",
+      "description": "The wielder deals 40.0% more Ice DMG and her QTE deals 40.0% more Total DMG; if wielded by Sixth Serenade, her Raven Mark deals 40.0% more Ice DMG, and she significantly gains Ignore Interrupt for 5s after unleashing weapon active or Combo ATK."
+    }
+  ]
+}