Shortcode for Widget

I could look into this, but if I would add it, it would just be a simple shortcode and would not have all the options for the widget. Would that suffice?

Alternatively, you can add widget areas to any templae and add a widget there.
Look into register_sidebar() to register a sidebar:
https://codex.ww.wp.xz.cn/Function_Reference/register_sidebar
and dynamic_sidebar() to display it in a template:
https://codex.ww.wp.xz.cn/Function_Reference/dynamic_sidebar

In version 2.1.4 there is now a ‘[gwolle_gb_widget]’ shortcode.