Modules
Plotto generates SVG and PNG charts in pure Elixir.
A bar chart: one or more series, each rendered as a group of bars per category,
bar height proportional to :value.
A candlestick chart: renders open-high-low-close (OHLC) financial and price data intervals as candlesticks with wicks and colored bodies.
A line chart: a single line connecting one point per data item.