Extend the documentation with more information about multidimensional ranges

[akukanov]

Summary

The oneTBB documentation lacks information about multidimensional ranges (blocked_range2d/3d) that the library provides. Once blocked_nd_range is added (see uxlfoundation/oneAPI-spec#555), it makes sense to mention it as well.

URLs

https://oneapi-src.github.io/oneTBB/main/tbb_userguide/Advanced_Topic_Other_Kinds_of_Iteration_Spaces.html - add information about multidimensional ranges
https://oneapi-src.github.io/oneTBB/main/tbb_userguide/parallel_for_os.html - consider adjust wording to mention other multidimensional ranges.