added yarn spinner package

NightclubArcadia/Packages/dev.yarnspinner.unity/Runtime/Commands/YarnParameterAttribute.cs

@@ -0,0 +1,18 @@
+/*
+Yarn Spinner is licensed to you under the terms found in the file LICENSE.md.
+*/
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+#nullable enable
+
+namespace Yarn.Unity.Attributes
+{
+    [AttributeUsage(AttributeTargets.Parameter, Inherited = false)]
+    public abstract class YarnParameterAttribute : Attribute
+    {
+    }
+}