Data viz: create_dir - Tack to fs package, a cross platform file system package

[libjohn]

data viz lesson | code @ lines 55-57

The Tidyverse packages are introduced, installed and loaded in earlier lessons. fs package is installed when install.packages("tidyverse"). Therefore, I propose using the fs package for file system manipulation. I think the fs package offers many advantages...

• cross platform
• many useful functions beyond the base-R equivalents
• functions are consistent across the fs package

Original

dir.create("data")
dir.create("data_output")
dir.craete(fig.output")

Proposed

library(fs)   # https://fs.r-lib.org/.  fs is a cross-platform, uniform interface to file system operations via R. 
dir_create("data")
dir_create("data_output")
dir_create("fig_output")

[libjohn]

merged https://github.com/LibraryCarpentry/lc-r/pull/31