Set label on x axis.
You can set x axis label and change its position by this option. string and object can be passed and we can change the poisiton by passing object that has position key. Available position
differs according to the axis direction (vertical or horizontal). If string set, the position will be the default.
Valid horizontal positions: inner-right (Default), inner-center, inner-left, outer-right, outer-center, outer-left
Valid vertical positions: inner-top, inner-middle, inner-bottom, outer-top, outer-middle, outer-bottom
Set padding for x axis.
If this option is set, the range of x axis will increase/decrease according to the values. If no padding is needed in the ragen of x axis, 0 should be set. On category axis, this option
will be ignored.