Add iOS platform to package

Author: kagemiku

Package.swift

@@ -1,23 +1,19 @@
 // swift-tools-version:5.2
-// The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
 
 let package = Package(
     name: "NavigatableCollection",
+    platforms: [
+      .iOS(.v13),
+    ],
     products: [
-        // Products define the executables and libraries produced by a package, and make them visible to other packages.
         .library(
             name: "NavigatableCollection",
             targets: ["NavigatableCollection"]),
     ],
-    dependencies: [
-        // Dependencies declare other packages that this package depends on.
-        // .package(url: /* package url */, from: "1.0.0"),
-    ],
+    dependencies: [],
     targets: [
-        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
-        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
         .target(
             name: "NavigatableCollection",
             dependencies: []),