I've made a Beta Page to test it out, here . I'm thinking of creating an infobox for it, but it's 6am rn haha
I think that having a page for things like "Heaviside Layer", "Jellicle Cats", "Jellicle Ball", "Junkyard", etc, outside of the musical numbers, to explain the concepts and such. Sorry for the wording on that page though, not so good.
Basically what I'm saying is that i love love our actor pages and shows and such... But having pages for the in-universe things too. It's like the Harry potter wiki having a page for Daniel Radcliffe, but also having a page for Hogwarts as the location, yknow?
I think a good category tag would be "Cats Universe"... if we decide against it we can always delete the page!