chore: Update environment variable seperator comment to indicate doub…

…le underscore (#164)

chore: Update env var comment to double underscore

rust/src.axum/settings.rs

@@ -104,8 +104,8 @@ impl Settings {
         let path = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("config/settings.toml");
         // inject environment variables naming them properly on the settings
         // e.g. [database] url="foo"
-        // would be injected with environment variable APP_DATABASE_URL="foo"
-        // use one underscore as defined by the separator below
+        // would be injected with environment variable APP__DATABASE__URL="foo"
+        // using a double underscore as defined by the separator below
         let s = Config::builder()
             .add_source(File::with_name(&path.as_path().display().to_string()))
             .add_source(Environment::with_prefix("APP").separator("__"))