Replace manual categorization by tags from shard.yml

[szabgab]

The manual catalogue has some some advantages, but it will be hard to scale it once there are tens of thousands of shards. It might be a better way to add a new field to the shard.yml called "tags" or "categories" that can contain a list of categories the authors feel fit to use for their shards. The values could be filtered by a fixed set of keywords.

[straight-shoota]

I think a centrally curated taxonomy is more valuable. It would be a real hassle to encourage a somewhat consistent categorization in the shards themselves, even with mechanisms like closed list of terms.
For a similar reason shardbox allows overriding the description. We could do the same for tags, but then we're close to what we have currently.

IMO it would create more problems and friction. Categorizing really isn't that hard. I have an idea for building an interactive UI for categorizing shards, that makes it even more accessible. I even had a working prototype but unfortunately, lost it due to being stupid 🙈

A curated taxonomy can very well work at a large scale (see https://www.ruby-toolbox.com/ for example).