Add widget support for categories

[juliazero]

Describe the problem

Translating two different projects from one organization, for example:

Organization

• Project1
• Project2

In one Weblate project, you can use categories to separate translations

• Project/category1/component(s)
• Project/category2/component(s)

Currently, Weblate widgets work for all components in project or for a selected one.

It would be nice if will be possible to set a widget for a category to count statistics from all components in the category.

Solution brainstorm

[![Translation status](https://hosted.weblate.org/widget/project/category/selected-widget.svg

Describe alternatives you have considered

No response

Screenshots

No response

Additional context

No response

[cebarobot]

I totally agree with this issue. Adding widget support for categories would be very useful for Markdown Projects, which have a lot of components (separate md files).

Would love to see this implemented. Thanks for the great work!