[documentation] `build-fs` and non-flattened filesystem structure?

[rmonat]

Let's suppose I have files foo and bar/foo. If I run js_of_ocaml build-fs -o fs.js foo bar/foo, the directory structure is forgotten and both files seem to be stored in /static/foo. Is there a way to keep the original directory structure with build-fs, in a way that is ideally, compatible with a source_tree option of dune?

In the worst case, it seems that js_of_ocaml build-fs -o fs.js foo:/static/foo bar/foo:/static/bar/foo works, but I find it a bit verbose and was wondering if there was something more concise.