title: Write multiple dataframes to same json object
body: <p>Using jsonlite package I am able to write a dataframe to json e.g.</p>
  <pre><code>library(jsonlite)
  library(tidyverse)
  
  mtcars %&gt;% toJSON() %&gt;% write('data/mtcars.json')
  diamonds %&gt;% toJSON() %&gt;% write('data/diamonds.json')
  </code></pre>
  <p>My question is, is it possible to add both mtcars and diamonds to the same json object?</p>