title: Plotly: Constant Spike lines for Candlestick Charts
body: <p>I am currently trying to add spikelines to my candlestick chart on Plotly in Python.</p>
  <p>I want the spikeline to follow the y-coordinates of my cursor/mouse no matter where my cursor is on the chart.  But right now, I can only get a spikeline when my cursor is on a candle.</p>
  <p>I have the following code for spikelines:</p>
  <pre><code>fig.update_yaxes(showspikes = True, spikecolor = '#FB75FF', spikedash = 'solid',
                       spikesnap = 'cursor', spikemode = 'across', spikethickness = 1)
      fig.update_layout(spikedistance = 1000, hoverdistance = 100)
  </code></pre>
  <p>It would also be nice if I can display the y-coordinate on the edge of the chart.</p>
  <p>Is this possible?</p>
  <p>Thank you.</p>