Document Experimental::sort_by_key

[dalg24]

Added in kokkos/kokkos#6801

[nliber]

Here is what appeared on the 4.3 briefing slide:

Introduced sort by key to dispatch to optimized vendor libraries

ExecutionSpace exec_space ;
Kokkos :: View <int *> keys (" keys ", n);
Kokkos :: View < float *> values (" values ", n);
Kokkos :: Experimental :: sort_by_key ( exec_space , keys , values );

▶ 1D views only
▶ Sizes of keys and values must match
▶ Both keys and values are modified
▶ Dispatches to vendor libraries (Thrust, rocThrust, oneDPL) when available