Function theme_setting_set 

pub fn theme_setting_set(
    config: &Config,
    discourse_name: &str,
    theme_id: u64,
    key: &str,
    value: &str,
    dry_run: bool,
) -> Result<()>

Set a single theme/component setting. The value is sent verbatim, so a JSON-schema list setting takes its JSON text directly.