Add Package.swift

Author: andreamazz

Package.swift

@@ -0,0 +1,16 @@
+// swift-tools-version:5.0
+import PackageDescription
+
+let package = Package(
+  name: "SubtleVolume",
+  products: [
+    .library(
+      name: "SubtleVolume",
+      targets: ["SubtleVolume"])
+  ],
+  targets: [
+    .target(
+      name: "SubtleVolume",
+      path: "Source")
+  ]
+)