The position of the axis to bind the values to. Possible values are 'left', 'bottom', 'top' and 'right'.
You must explicitly set this value to bind the values of the line series to the ones in the axis, otherwise a
relative scale will be used. For example, if you're using a Scatter or Line series and you'd like to have the
values in the chart relative to the bottom and left axes then axis should be ['left', 'bottom'].
Defaults to: "left"