ADD a `canResize: true` example window

[allanlaal]

currently all the opened windows have WindowStyle canResize: false, which will leave users thinking nativeshell does not support window resizing :confused:

[knopp]

Not quite sure what you mean, the main window is resizable.

[allanlaal]

yes, but the new windows feel like nativeshell magic. there are frameworks that can only make half-assed windows (like whatever IntelliJ is using)

[allanlaal]

perhaps an explicit resizeable modal?