Visualize visualize benchmark sets and save html to target path every set will be visualize as 3+ bar charts for 3+ metrics(include custom metrics), and be exported to html files in the given saveDir @Concept alignment: bench.Set(package) -> page(html) metrics(ns/op...) -> series of metrics value targets -> series name(x axis) scenarios -> dummy values in charts(group name) @param saveDir string @param sets []bench.Set @return savedPaths []string @return err error @author kevineluo @update 2023-03-07 02:14:40.