doc: Document frameless window.

docs/browser-window.md

@@ -15,6 +15,10 @@ win.loadUrl('https://github.com');
 win.show();
 ```
 
+You can also create a window without chrome by using
+[Frameless Window](frameless-window.md) API.
+
+
 **Note:** Be careful not to use `window` as the variable name.
 
 ## Class: BrowserWindow
@@ -38,6 +42,8 @@ win.show();
   * `kiosk` Boolean - The kiosk mode
   * `title` String - Default window title
   * `show` Boolean - Whether window should be shown when created
+  * `frame` Boolean - Specify `false` to create a
+    [Frameless Window](frameless-window.md)
 
 Creates a new `BrowserWindow` with native properties set by the `options`.
 Usually you only need to set the `width` and `height`, other properties will