v2.6.4

VueUiXyCanvas #168

• Fix scale issue in stack mode
• Add optional dataset attribute showYMarker to display a data label on the Y axis when hovering the chart
• Add config attribute to show an horizontal selector when hovering the chart:

config.style.chart.selector.showHorizontalSelector: boolean; // default: false

Color pickers (built-in annotator from the user options menu in most charts)

• Improved accessibility