Update example

Author: kateinoigakukun

Example/JavaScriptKitExample/Sources/JavaScriptKitExample/main.swift

@@ -1,7 +1,7 @@
 import JavaScriptKit
 
-let alert = JSObjectRef.global.alert.function!
-let document = JSObjectRef.global.document.object!
+let alert = JSObject.global.alert.function!
+let document = JSObject.global.document.object!
 
 let divElement = document.createElement!("div").object!
 divElement.innerText = "Hello, world"
@@ -10,8 +10,9 @@ _ = body.appendChild!(divElement)
 
 let buttonElement = document.createElement!("button").object!
 buttonElement.innerText = "Click me!"
-buttonElement.onclick = .function { _ in
+let listener = JSClosure { _ in
     alert("Swift is running on browser!")
 }
+buttonElement.onclick = .function(listener)
 
 _ = body.appendChild!(buttonElement)