Fetch more articles for current feed or category

[jocmp]

Discussed in #532

^{Originally posted by Alkarex November 20, 2024}
In the GReader API, it is possible to fetch articles for a given feed or for a given category.
This is especially useful when there are many articles on the server (more than what the app is fetching) and the user wants to fetch older articles for a given feed or category.

So in the CapyReader app, it would be nice if the "pull to refresh" feature, when done from within a feed or a category, would fetch articles from that feed or category.

I can give more details if this is not clear enough, and do not hesitate to ask for help on back-end side (FreshRSS).