New feature: included categories

Hi,

this is not a bug… maybe a new feature.

Imagine you have 4 main categories, each with 50 child categories…
If you want to show in each of this 4 main categories top 10 posts, you may do that configuring each widget with a shortcode that exclude all other 150 categories. Imagine the length of this shortcode!…

What if, besides excluded categories, we’ve “included categories”?!

Thanks.
Marco