Add possibility to categorize articles in Reading List and Archive

Description

Right now, the Reading List and Archive contain a flat list of articles you saved to read later. The problem appears if you have many articles saved (I have +100, for example ). Many times I was thinking that it would be awesome to have the possibility to create custom lists/shelves/sections for categorising articles (for example, I could name them "for my next project", "inspiration", etc.). It would be good to have such an option in Archive as well, since it happened to me that I was looking for an article I archived and couldn't find it. Such custom sections/shelves/lists could help arrange the list of articles a bit.

What it could look like

Not sure what would be the easiest to implement (especially since I am not an engineer), but I'll drop some inspirations below. For example, such a feature could look like Gmail labels:

Another option is the possibility of adding custom shelves. The screenshot below shows a Polish book portal where users can add books they read to one of the custom shelves:

... or maybe there is another idea that would solve the issue of people having multiple articles saved :) Looking forward for more suggestions!