User:Enterprisey/parent-cats

When a page is categorized in both a category and a parent of that category (for example, if a page is in Birds and also Animals - Animals is a parent of Birds), highlight both in the categories list at the bottom of the page.

This script was written during a single lightning talk (OK, well, two lightning talks) at WikiConference North America 2023. Thanks Buidhe for suggesting it!