add weapon skin & command for it

Common/Data/Excel/WeaponSkinExcel.cs

@@ -0,0 +1,24 @@
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+namespace MikuSB.Data.Excel;
+
+[ResourceEntity("weapon_skin.json")]
+public class WeaponSkinExcel : ExcelResource
+{
+    public uint Genre { get; set; }
+    public uint Detail { get; set; }
+    public uint Particular { get; set; }
+    public uint Level { get; set; }
+    public string I18n { get; set; } = "";
+
+    public override uint GetId()
+    {
+        return (uint)I18n.GetHashCode();
+    }
+
+    public override void Loaded()
+    {
+        GameData.WeaponSkinData.Add(GetId(), this);
+    }
+}