/**
* Configuration properties for gridlines.
*
* @public
* @module GridLineConfig
*
* @param {boolean} show Whether to show or hide the grid line. By default true for vertical gridlines.
* @param {string} zeroLineColor Color of zero line.
* @param {string} color Color of grid lines.
* @param {Object} x Configuration of grid lines drawn along x axis.
* @param {boolean} x.show Whether to show or hide vertical grid lines.
* @param {Object} y Configuration of grid lines drawn along y axis.
* @param {boolean} y.show Whether to show or hide horizontal grid lines.
*/