rmarkdown 2.20

• The defunct tufte_handout() has been removed from rmarkdown. Please use tufte::tufte_handout() instead.

• If an input path to rmarkdown::render() is a symbolic link, it is no longer resolved to its real path (thanks, @SamDM @jmw86069, #1508).

• Make sure to avoid creating invalid paths when copying resources (thanks, @mnazarov, #2429).

• Make sure logo is properly embedded in ioslides_presentation() when self_contained = TRUE (thanks, @mnazarov, #2428).