Feature: make Reader use center window

App/Scene Delegates/SettingsSceneDelegate.swift

@@ -0,0 +1,28 @@
+//
+//  SettingsSceneDelegate.swift
+//  SBrowser
+//
+//  Copyright © 2021 Apple Inc. All rights reserved.
+//
+
+import UIKit
+
+class SettingsSceneDelegate: UIResponder, UIWindowSceneDelegate {
+    var window: UIWindow?
+    
+    var settingsViewController: SettingsViewController?
+
+    func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions)
+    {
+        guard let windowScene = (scene as? UIWindowScene) else { return }
+        
+        let window = UIWindow(windowScene: windowScene)
+        let settingsViewController = SettingsViewController(windowScene: windowScene)
+        self.settingsViewController = settingsViewController
+        window.rootViewController = settingsViewController
+        windowScene.sizeRestrictions?.maximumSize = CGSize(width: 760.0, height: 400.0)
+        
+        window.makeKeyAndVisible()
+        self.window = window
+    }
+}