Made background music and started on difficulty slider

Assets/Scripts/DifficultyManager.cs

@@ -0,0 +1,20 @@
+using UnityEngine.UI;
+using UnityEngine;
+
+namespace InterfaceOff.MainMenu
+{
+    public class DifficultyManager : MonoBehaviour
+    {
+        public static float DifficultyMultiplier { get; private set; } = 1;
+        [SerializeField] private Slider DifficultySlider;
+
+        private void Awake()
+        {
+            DifficultySlider.onValueChanged.AddListener((val) =>
+            {
+                DifficultyMultiplier = val / 4f; // Makes it between 0.75 and 1.25
+                Debug.Log("Difficulty Slider: " + DifficultyMultiplier);
+            });
+        }
+    }
+}