New features r2resize since 1.3: Resizeable Expandable Splittable containers and boxes in R

Authored by:Obinna N. Obianom inr2resize 1.9.1.
Source:resizable_containers_split_screen_r2resize.Rmd, Vignette:resizable_containers_split_screen_r2resize.html. Last updated:2023-01-30.