title: Format or styling label in apache echarts markLine
body: <p>I need format label in the markline. Is possible add image backround, or in general custom styling?.</p>
  <p>Is possible draw the markLine over the candles?, because at the moment when the markline goes down, the candles cover the label.</p>
  <p><a href="https://i.stack.imgur.com/BKBT0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/BKBT0.png" alt="number in the markLine label" /></a></p>
  <p>I would like to do something like what is shown this picture:</p>
  <p><a href="https://i.stack.imgur.com/y6vOC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/y6vOC.png" alt="label styling" /></a></p>
  <p>EDIT:
  This is my actual code</p>
  <pre><code>            m.setOption(
              {
                  series: {
                      markLine: {
                          symbol: 'none',
                          label:
                              {
                                  position: 'middle',
                                  show: true,
                              },
                          lineStyle: {
                              color: mc,
                              //type: 'solid'
                          },
                          data: [{yAxis: window.wsData[1], name: 'Tiker'}],
                          position: 'insideStartTop'
                      }
                  }
              }
          )
  </code></pre>