docs: fix incorrect comment on machine_readable

sdgb-cli/src/commands.rs

@@ -5,7 +5,9 @@ use strum::EnumString;
 #[derive(Parser)]
 #[command(about = "SDGB api tool", long_about = env!("CARGO_PKG_DESCRIPTION"))]
 pub struct Cli {
-    /// try to generate human readable output.
+    /// Try to generate machine readable format.
+    ///
+    /// You must specify this for `-f, --format` to take effect.
     #[arg(short = 'M', long)]
     pub machine_readable: bool,
     #[command(subcommand)]
@@ -50,7 +52,7 @@ pub enum Commands {
         /// JSON format.
         ///
         /// `origin`: official json response
-        /// 
+        ///
         /// `dx_rating_net`: DxRatingNet Format
         #[arg(short, long, default_value_t = RatingFormat::default())]
         format: RatingFormat,