Specifies the title for the argument axis.
If you only wish to set the text for the axis title, assign this text to the title property directly. Set the text property and other properties of the title configuration object if you need to customize title options. For an overview of axis titles, refer to the Axis Titles topic.
If you need to set a common value for the titles of all axes, use the commonAxisSettings | title configuration object. It exposes the properties that can be specified for titles of all axes at once. Note that the values specified for the argument axis individually (in the argumentAxis | title object) override the values that are specified for all axes (in the commonAxisSettings | title object).