hc_add_series for xts objects

Usage

# S3 method for xts
hc_add_series(hc, data, ...)

# S3 method for ohlc
hc_add_series(hc, data, type = "candlestick", ...)

hc: A highchart htmlwidget object.
data: A xts object.
...: Arguments defined in https://api.highcharts.com/highcharts/plotOptions.series.
type: The way to show the xts object. Can be 'candlestick' or 'ohlc'.