added "using" statement to code example

Author: duckets

Packages/com.unity.inputsystem/InputSystem/Plugins/PlayerInput/InputValue.cs

@@ -51,6 +51,8 @@ public object Get()
         ///
         /// <example>
         /// <code>
+        /// using UnityEngine;
+        /// using UnityEngine.InputSystem;
         /// [RequireComponent(typeof(PlayerInput))]
         /// public class MyPlayerLogic : MonoBehaviour
         /// {