Enable radio buttons to select which content can be seen on library.kiwix.org

[Popolechien]

The current selection for categories is that we chose to display only one category:

But with Maps and Youtube, we now are entering a period where there's a lot of repetitive clutter that can not be easily parsed. It would be better to be able which categories should be displayed, via radio buttons.

[rgaudin]

@Popolechien, as for @kelson42, please refrain from adding good first issue label.

A good first issue is a ticket that is (surprise) as the name suggest, a good first-contribution to this repo: the ticket is clear, has no pending question, implementation is either already discussed or trivial.

In general, only maintainers should set it as subtle details can change the nature of ticket drastically.