Update to adwaita-swift 0.2.0

Package.swift

@@ -6,7 +6,7 @@ import PackageDescription
 let package = Package(
     name: "Adwaita Template",
     dependencies: [
-        .package(url: "https://github.com/AparokshaUI/Adwaita", from: "0.1.5")
+        .package(url: "https://github.com/AparokshaUI/Adwaita", from: "0.2.0")
     ],
     targets: [
         .executableTarget(

Sources/AdwaitaTemplate.swift

@@ -16,10 +16,8 @@ struct AdwaitaTemplate: App {
                 .topToolbar {
                     ToolbarView(app: app, window: window)
                 }
-                .onAppear {
-                    window.setDefaultSize(width: 450, height: 300)
-                }
         }
+        .defaultSize(width: 450, height: 300)
     }
 
 }