Simplifies custom 'CSS' styling of both 'shiny' and 'rmarkdown' via
'Bootstrap' 'Sass'. Supports both 'Bootstrap' 3 and 4 as well as their
various 'Bootswatch' themes. An interactive widget is also provided
for previewing themes in real time.

Homepage:
https://CRAN.R-project.org/package=bslib
