Hi, and welcome!
Quick overview of the chain to create PDF:
rmarkdown -> pandoc -> MIKTEX -> pdf
The rmarkdown
takes care of installing pandoc
, but it's up to the user to install MIKTEX (in WinWorld) where it's expected.
The POLR
(path of least resistance) here is to move pdflatex.exe
to C:/Users/jsnyd/AppData/Local/Programs/MIKTEX~1.9/miktex/bin/x64
, along with any other files in its current directory. (I'd be more precise, but I haven't been troubled with Windows since XP.)