bin/map: Fix comment formatting.

bin/map/src/main.rs

@@ -51,8 +51,8 @@ impl Map {
         }
     }
 
-     //--> {"jsonrpc": "2.0", "method": "say_hello", "params": [], "id": 42}
-     //<-- {"jsonrpc": "2.0", "result": "hello world", "id": 42}
+    // --> {"jsonrpc": "2.0", "method": "say_hello", "params": [], "id": 42}
+    // <-- {"jsonrpc": "2.0", "result": "hello world", "id": 42}
     async fn say_hello(&self) -> Result<Value> {
         let req = jsonrpc::request(json!("say_hello"), json!([]));
         Ok(self.request(req).await?)