Function config 

fn config(
    config_dir: &Path,
    orgs: &[(&str, &[&str])],
    server: &str,
    env: &[(&str, &str)],
    tts_enabled: bool,
) -> String

The forge.toml a fleet is built from: one [[orgs]] per entry, each project under its own directory so two projects never share a path.