Add link to Boolean

docs/styleguide.md

@@ -170,6 +170,7 @@ of argument is notated by either the common types:
 - [`Number`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)
 - [`Object`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)
 - [`Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)
+- [`Boolean`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)
 - Or a custom type like Electron's [`WebContent`](api/web-content.md)
 
 If an argument or a method is unique to certain platforms, those platforms are