title: Increase width of entire HTML Rmarkdown output
body: <p>I am looking to increase the overall width of my HTML Rmarkdown output. </p>
  
  <p>When producing PDF documents from Rmarkdowns there is an option to set the margin in the YAML section of the Rmd (ex. geometry: margin=.5in).</p>
  
  <p>I am looking for something similar for HTML docs. The following link is a good example of my issue: <a href="https://rstudio.github.io/DT/extensions.html" rel="noreferrer">https://rstudio.github.io/DT/extensions.html</a> </p>
  
  <p>As you can see on that html webpage, there is a lot of white space to the left and right of the datatables. Is there a way to reduce this margin space and thus increase the width of the datatables?</p>
  
  <p>Thanks</p>