How to to change all font to be the same for PDF output?

[rbcavanaugh]

I've been looking through the documentation and I'm can't find the answer (apologies, I'm not as familiar with PDF output and have minimal understanding of latex).

In a normal pdf output, the title/header fonts are sans-serif while the text itself is a serif font. How can I make all font the same in the pdf. (e.g., all serif, such as time new roman or all sans-serif, such as Helvetica). I tried changing the mainfont and sansfont arguments without any luck. thanks!

[rbcavanaugh]

I was able to get this to work using the following, but I perhaps there could be a more thorough (step-by-step) guide/vignette for modifying the .pdf formatting (especially the title page, font, font-size) for those of us who don't have a strong grasp of latex.

format: 
    pdf:
      shift-heading-level-by: 2
      mainfont: Times New Roman
      sansfont: Times New Roman