build_js: Compress and optimize all files in the current folder
In RinteRface/charpente: Seamlessly design robust 'shiny' extensions

Generates a minified file under inst/pkg_name-pkg_version, if mode is prod. If mode is dev, aggregates all js files without mangling or compression.

1	build_js(dir = "srcjs", mode = c("prod", "dev"), entry_point = "main.js")

`dir`	Default to srcjs.
`mode`	Production or development mode. Choose either "prod" or "dev". "prod" bundles, aggregates and minifyies files. "dev" only bundles the code. Modules follow the ES6 format (import/export).
`entry_point`	Required internally to setup the esbuild config.