feat: better show method for RNTuples

[ariostas]

This PR improves the show method on RNTuple so that it better shows the structure. This was inspired by UnROOT, which does a much better job of displaying the contents of an RNTuple.

This change breaks the api, but I think it's fine since show is something you would only use interactively and not in some existing script.

I still have to do some polishing and maybe add colors.

[ariostas]

I added **kwargs just no not break the api, and I fixed the docstring. I think it's not worth adding color since that might complicate things and might not always work.

[ianna]

@ariostas - looks good to me. Thanks! I’m not sure why docs are failing though.

[ariostas]

@jpivarski or @agoose77 could you please add Ianna and me as maintainers in ReadTheDocs? The build randomly fails, so it would be nice to be able to retry it easily.

[jpivarski]

I added you, @ariostas, but I don't know @ianna's ReadTheDocs account (or the associated email address; I tried all the email addresses that I know).

[ariostas]

Thank you, Jim!

[ianna]

I added you, @ariostas, but I don't know @ianna's ReadTheDocs account (or the associated email address; I tried all the email addresses that I know).

Thanks @jpivarski ! I have an account linked to my GitHub and cern email ianna dot osborne at cern dot ch

[jpivarski]

That's an email address that I tried, among with your GMail and Princeton ones. Do you log into ReadTheDocs (.org) using your GitHub account? If so, your GitHub username should have worked, but that didn't either.

[ianna]

That's an email address that I tried, among with your GMail and Princeton ones. Do you log into ReadTheDocs (.org) using your GitHub account? If so, your GitHub username should have worked, but that didn't either.

Could you please try again? Thanks

[ariostas]

@ianna I just added you and it seems to have worked