feat: add Button API

lib/browser/api/button.js

@@ -0,0 +1,15 @@
+'use strict'
+
+const electron = require('electron')
+
+const {View} = electron
+const {Button} = process.atomBinding('button')
+
+Object.setPrototypeOf(Button.prototype, View.prototype)
+
+Button.prototype._init = function () {
+  // Call parent class's _init.
+  View.prototype._init.call(this)
+}
+
+module.exports = Button