title: Change size of section titles in R Markdown PDF
body: <p>Is there a way to change the font size of text of headings in R Markdown?</p>
  
  <p>I know how to number the sections of the article; however, in terms of formatting, the font size of the sections that are numbered <code>1., 2., 3...</code> is <em>too large</em>. As a workaround, I have been using lower-level headers <code>### Introduction</code>, but these have the wrong numbering.</p>
  
  <p>Here is a basic example:</p>
  
  <pre><code>---
  output: bookdown::pdf_document2
  ---
  
  # This is too big
  
  ### This is the right size but are labelled as 1.0.1
  </code></pre>