title: Showing counts and percentages in echarts4r `e_pie` pie charts
body: <p>I would like to plot the counts and/or percentages in a donut chart created by <code>e_pie</code> from echarts4r.</p>
  <p>This is the <a href="https://echarts4r.john-coene.com/articles/chart_types.html" rel="nofollow noreferrer">link</a> for the documentation.</p>
  <p>The below is the example from the documentation, yielding the following donut chart without counts and percentages:</p>
  <pre class="lang-r prettyprint-override"><code>mtcars %&gt;% 
    head() %&gt;% 
    dplyr::mutate(model = row.names(.)) %&gt;% 
    e_charts(model) %&gt;% 
    e_pie(carb, radius = c(&quot;50%&quot;, &quot;70%&quot;)) %&gt;% 
    e_title(&quot;Donut chart&quot;)
  </code></pre>
  <p><a href="https://i.stack.imgur.com/G2sLK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/G2sLK.png" alt="enter image description here" /></a></p>
  <p>What I am looking for is something achieved like this from R plotly:</p>
  <pre class="lang-r prettyprint-override"><code>mtcars %&gt;% 
    head() %&gt;% 
    dplyr::mutate(model = row.names(.)) %&gt;% 
    plot_ly(labels = ~ model,
                      values = ~ carb,
                      textinfo = 'value+percent',
                      marker = list(colors = c(&quot;#ABDDDE&quot;,&quot;#F8AFA8&quot;),
                                    line = list(color = '#000000',
                                                width = 0.75)
                                    )
            ) %&gt;%
      add_pie(hole = 0.6) %&gt;%
      layout(title = &quot; Donut chart&quot;, showlegend = T)
  </code></pre>
  <p><a href="https://i.stack.imgur.com/tlT0g.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tlT0g.png" alt="enter image description here" /></a></p>