title: How to customize hover information in ggplotly object?
body: <p>Is there a way to customize hoverinfo in a ggplotly object? </p>
  
  <p>For example,</p>
  
  <pre><code>p &lt;- ggplot(mtcars, aes(x = disp, y= am, color = as.factor(cyl)))+geom_point()
  
  ggplotly(p)
  </code></pre>
  
  <p>The hover information box here contains three variables:disp,am and factor(cyl). How to include more variables or exclude existing variables in the hover information box?</p>
  
  <p>Thanks!</p>