Add tags for categories, topics and stuff.
- define them in the blog.json including color
- render them like a gitlab tag (see below)

coloring method 1
- configure them within each metadata json within a
tags map
- let rendering fail if tag is used but not defined
coloring method 2
- convert tag into color deterministicly
Add tags for categories, topics and stuff.
coloring method 1
tagsmapcoloring method 2