title: How to insert plain picture (jpeg / png) from chunk with knitr
body: <p>I want to insert a picture at the beginning of text using a code block, not markdown. I am using the Tufte handout template <code>output: rmarkdown::tufte_handout</code> and when I insert it straight after the YAML header but before TOC like this:</p>
  
  <pre><code>\centering
  ![width='100%'](./cropped-banner_efpt.jpg)
  \raggedright
  \tableofcontents
  \clearpage
  </code></pre>
  
  <p>the image then spans the main body. I know that with chunks there is an option to have the chunk to span the whole page placing <code>fig.fullwidth = TRUE</code> in the chunk header, but I am a bit stuck with this as I am not generating any graph from data and I do not know how to simpy place an image from within a chunk. </p>
  
  <p>Another matter was that when I set toc: true in the YAML header, the image would only come <em>after</em> the inserted toc - that is why I am inserting toc with the latex command. </p>
  
  <p>Thank you for your suggestions.</p>