no documentation for solid start --config-path or --config-file

The output of solid start --help doesn't show any help description for the following items:

--config-path [value]
--config-file [value]

What's more, the output of solid init doesn't make this very clear either:

? Path to the config directory (for example: /etc/solid-server) ./myconf
? Path to the config file (for example: ./config.json) foo.json

When I see these items, I ask the following questions:

1. should the config file be stored in the config directory, or are these different things? I expected that the config file would be written as [config_dir]/[config_file], but it isn't. Is the config directory something for startup, or runtime configuration?
2. if I specify foo.json as a config file, why does solid init still write it to ./config.json?
3. I can specify a config file on the command line with solid start --config-file. If it reads this config file, what is the behaviour of the configFile option in this json file? Is it used at all (to reload a secondary config file?) or is it ignored?

Start by running solid start --help and solid init, then trace the --config-path, --config-file, and configFile entry points to establish their behavior. Update the relevant CLI help or documentation so the relationship between the config directory, config file, and generated ./config.json is explicit, and verify the documented behavior against both commands.