Docs subpages with a single item should just show it immediately

[ricardoV94]

No reason to require a double click in these cases... unless it's too much work to change the behavior of course :)

[OriolAbril]

are there other cases of this?

This is also related to #5282. Do we want pm.Censored to have its own subsection or do we want to restructure the subsections inside "Distributions"

[ricardoV94]

There are couple more, Simulator comes to mind.

I think our docs structure does not need to follow the project one

[OriolAbril]

closed by #6781