I concur with the dissenters here. I think it is natural and intuitive to just use subcategories for exactly the same purpose.
It would be awesome if the sub-categories/folders could also be presented as books, like parent categories. It would make navigation easier and is visually more pleasing.
I will say I understand why this feature might be useful- the way I organise my article using categories is very different from the way I’d organise them if I had private folders for myself, mostly because category organisation is oriented towards other people while folders would be personal to me. That said, as others have mentioned this can be done via tags- I myself am only starting to use them so the following suggestion might be dumb / already in place (and I can’t really check rn), but maybe having a page that acts as a tag manager of some kind and lets you organise tags in different folders could be nice? And where clicking on a tag would display all articles tagged with it? (Again if smth similar already exist please ignore me!)
You can simply add a category within a category, which is a folder for articles
Seems like analogous functionality already exists? You can make subcategories inside exiting categories. You can also tag your articles for easier searching.
I'm a little bemused by this one, as your own request gives away the key word: "...group things up into *categories*..." That's exactly what I've done to keep my articles neatly organised for my own D&D campaign: categories can be created inside of categories. For example, I have my campaign category folder, with a sub-category of NPCs, then a sub-sub-category for the location where each NPC is. Also, you can add searchable tags to each article, which will bring it up in search results. If you want something prettier, it's easy to create pages which do nothing but automatically list every article with a specific tag, showing the name & excerpt, linking straight to that article. So for a large town I have a Dramatis Personae page, which has a list of all the merchant NPCs, followed by a list of the Town Watch NPCs, followed by a list of the other characters. This one's a solution in search of a problem, I think.
I don't think I get what you are looking for? You can make sub-categories within categories already. (as in folders within folders?) I am guessing that the issue is, that you can't have an article in more than one category, which means you have to pick one way of putting content into categories. However, I would strongly suggest you look at tags. I didn't use them at first, but they are amazing. You can automatically generate lists of one tag (e.g. list all entries with the tag #potion) so you can then set up an article with the tags listed. Another option might be content trees. you can add articles manually and sort them the way you want them, so you could make a content tree for all the potions, or weapons or whatnot. They might be locked behind a higher tier level, though. I'm not quite sure right now. TL;DR: What you are looking for might already be possible, just in a slightly different way?
You can put a category inside a category, a category is like a folder
Why not combine subcategories and tags? If you tag items as "potion", you could then use the (ignore the --) [ --tagged:potion|block|Potions] command in an article to display links to all potions.
This is what the categories / sub-categories we currently have .. are?! I have no idea what you are on about Nightstroud - Have you read any of the documentation mate?
As an additional feature I'd say definitely yes. As long as it doesn't replace anything we have right now