rmarkdown 2.24

• Fixed file_scope being lost when extending output formats that considers the file_scope using output_format(). Merge behavior is to apply overlay file_scope function onto the result of base_format's file_scope function. This implies that file_scope gains second argument which receives the returned values of the base file_scope (thanks, @atusy, #2488).

• Added output_format_dependency() which allows extending output format from within chunks (thanks, @atusy, #2462)

• Fix an issue with shiny prerendered document where dependencies context were written twice leasing to parsing error (thanks, @gadenbuie, rstudio/learn#597, #2500).