Implemented the WindowRouter router for iOS platform.

Sources/Coordinator/Platform/iOS/Routers/WindowRouter.swift

@@ -0,0 +1,43 @@
+//
+//  WindowRouter.swift
+//  Coordinator
+//
+//  Created by Javier Cicchelli on 11/04/2023.
+//  Copyright © 2023 Röck+Cöde. All rights reserved.
+//
+
+import UIKit
+
+/// This class is responsible for populating the window of an application.
+public class WindowRouter: Router {
+    
+    // MARK: Properties
+    
+    /// The window to set manually with a `UIViewController` view controller instance.
+    private let window: UIWindow?
+    
+    // MARK: Initialisers
+    
+    /// Initialise this router.
+    /// - Parameter window: A `UIWindow` window instance to be set manually.
+    public init(window: UIWindow?) {
+        self.window = window
+    }
+    
+    // MARK: Functions
+
+    public func present(
+        _ viewController: UIViewController,
+        animated: Bool,
+        onDismiss: OnDismissedClosure?
+    ) {
+        window?.rootViewController = viewController
+
+        window?.makeKeyAndVisible()
+    }
+    
+    public func dismiss(animated: Bool) {
+        // Nothing to do here...
+    }
+    
+}