I’ve updated this component and moved its repository to GitLab: Manuel Kostka / Discourse / Components / Featured Topics · GitLab.
The new version takes a slightly different design approach by removing select style options from the theme settings. Instead, it provides two basic layout arrangements (Cards and List) and a cleaner template for adding custom style declarations via CSS.
If you want to keep using the previous component it is available at GitHub - nolosb/discourse-featured-cards.