Add vector4 mutable variable reference

Author: Fireball19

Packages/SOVariables/Runtime/Mutable/Reference/Vector4MutableVariableReference.cs

@@ -0,0 +1,12 @@
+using UnityEngine;
+
+namespace RaCoding.Variables
+{
+    [System.Serializable]
+    public class Vector4MutableVariableReference : MutableVariableReference<Vector4>
+    {
+        [SerializeField] private Vector4MutableVariable vector4MutableVariable;
+
+        protected override MutableVariable<Vector4> Reference => vector4MutableVariable;
+    }
+}