Creating both html and pdf documents with bookdown

I added to the GitHub repository Examples of use of rmarkdown for creating pdf-files an example of the use of bookdown to create with one Rmd file both html and pdf documents. The inputs can be found in the input_bookdown folder and the results in the output_bookdown folder. In the description in the .Rmd file I wrote down my objectives:

• produce a text that would display well in both html and pdf format. I could not do this without including some switches related to the output format using knitr::is_latex_output and knitr::is_html_output
• produce tables and figure with a caption below the table or figure with a possiblity to reference them
• use css files to ensure that the table entries are not too close to the borders and that the tables with caption are centered in the html output. See the mycss.css file
• use text references to refer to a text (optionally with special html or latex characters). This is used here only for the tables. Note that a text reference must be in a separate paragraph with empty lines above and below it
• integrate the possibilities that the myknit function (from the HOQCutil package) offers to produce documents with a version number
• use references to a bibliography and sections of text (see the files book.bib and packages.bib)
• change the font of the pdf document to a non-serif one (see the preamble.tex file)
• try out methods to make the document self describing concerning the creation of tables and figures. In doing this I relied heavily on the concept of zero-width space. See the .Rmd file in a text editor that is capable of showing zero-width spaces such as the RStudio IDE