Added Loop Points to the Boo Menu and Pack Support

Only put this commit here since A: It's related to the BGM files, and B: It's dependent on the previous commit.

Assets/Audio/BGM/BooMenu.bgm

@@ -0,0 +1,10 @@
+{
+    "Normal": {
+        "source": "BooMenu.mp3",
+        "loop": 4.797
+    },
+    "Hurry": {
+        "source": "BooMenu.mp3",
+        "loop": 4.797
+    }
+}

Assets/Audio/BGM/BooMenu.json

@@ -0,0 +1,7 @@
+{
+	"variations": {
+		"default": {
+			"source": "BooMenu.bgm"
+		}
+	}
+}