create markdown docs for fx subcommands
usage: fx helpdoc [OPTIONS] OUTPUT_DIR
Create markdown documentation for fx and its subcommands, based on
the same metadata that is used to create the output of `fx help`
--vendor create docs for subcommands in //vendor/*/scripts/devshell.
If specified, only vendor docs are documented. There's
no way to generate docs for vendor and non-vendor at the
same time.
--toc-prefix URL_PREFIX use URL_PREFIX instead of "/reference/tools/fx"
as an URL prefix in generated _toc.yaml files.
--no-deprecated do not create docs for deprecated subcommands
--no-contrib do not create docs for contrib scripts in //tools/devshell/contrib/*