stdalgos (10/10): team-level API, and rst update for release 4.2

[antoinemeyer5]

Add team-level API to and convert to rst the following algorithms:

Kokkos_PartitionPoint.hpp
Kokkos_AdjacentDifference.hpp
Kokkos_Reduce.hpp
Kokkos_TransformReduce.hpp
Kokkos_ExclusiveScan.hpp
Kokkos_TransformExclusiveScan.hpp
Kokkos_InclusiveScan.hpp
Kokkos_TransformInclusiveScan.hpp

NOTE: this follows the new structure for documenting the API, but does not use sphinx because the lack of properly aligning things make things quite unreadable.

Open individual html with Firefox (must be firefox or it won't display correctly)

[ajpowelsnl]

@antoinemeyer5 , @fnrizzi , @crtrott -- Looks good; only potential (future) "gotcha" is the warning about methods being in Kokkos::Experimental namespace. This "gotcha" will be true for a number of the std::algorithms entries.