add shovel and digging, basic item interaction

Assets/Scripts/BurriedItem.cs

@@ -0,0 +1,13 @@
+using UnityEngine;
+
+public class BurriedItem : Diggable
+{
+    public GameObject ItemToSpawn;
+    public Transform Spawnpoint;
+
+    public override void Dig()
+    {
+        Instantiate(ItemToSpawn, Spawnpoint.position, Spawnpoint.rotation, null);
+        Destroy(gameObject);
+    }
+}