enhance documentation of fp:unzip to address more than pairs

fp:unzip works as one would hope, but that is not clear from the documentation, which speaks of "paired together" and gives examples only of a list containing two inner lists. It would be great is the documentation addressed the effect on a list of n lists, with n>2. Or if the current correct (in my exploration) behavior is not guaranteed, please state that in the documentation. But I hope it is! (Just to be clear about my personal interest, I care only about the rectangular case, where the inner lists have a common length.) Thanks!

Start by locating the documentation for fp:unzip and compare its stated behavior with rectangular lists containing more than two inner lists. Done when the documentation explains the n>2 behavior and clearly states whether that behavior is guaranteed.