Documentation: Rounding blog minor update needed

[rossfarrugia]

Let us know where something needs a refresh or put your idea here!

A colleague of mine spotted that https://pharmaverse.github.io/blog/posts/2023-07-24_rounding/rounding.html is not quite accurate for SAS. It sas "SAS rounds half up" but actually SAS rounds away from zero. You can see the difference in the negative numbers. In half up, -1.15 would round up to -1.1 instead of -1.2.

CAMIS says the same: https://psiaims.github.io/CAMIS/Comp/r-sas_rounding.html

[bms63]

@kaz462 addendum to your blog? :)