refactor: template of including files (#707)

src/config/input.rs

@@ -73,7 +73,7 @@ impl Input {
             texts.push(String::new());
         }
         for (path, contents) in files {
-            texts.push(format!("{path}:\n{contents}\n"));
+            texts.push(format!("{path}:\n``````\n{contents}\n``````\n"));
         }
         let (role, with_session, with_agent) = resolve_role(&config.read(), role);
         Ok(Self {