cross-link reverse functions to not miss other supported types

[avehtari]

fixes #798

unified also the section and anchor names

[WardBrian]

I am curious if there is a way we could do this somewhat automatically. Or at least link to the index, maybe?

[avehtari]

@WardBrian should this be closed as you did #803 ?

[WardBrian]

Maybe? I think its worth leaving #798 (possibly with a new title) to note that there could still be a smarter re-organization of the various overloads, but it is true for functions beyond just reverse (I myself ran into it last week with log_sum_exp living on two different pages)

[avehtari]

@WardBrian , checking if you are now more confident whether this should be closed, and what we should do with #798?

[WardBrian]

I think this can be closed, but it's probably still worth thinking if we should reorganize the functions by what they do rather than what types they work over, which would be the real solution to #798