fix doc test

README.md

@@ -1,2 +1,2 @@
 ## Intro
-> use rust implement minimum grep program.
+> use rust implement minimum grep cli program.

src/lib.rs

@@ -59,6 +59,7 @@ impl Config {
     /// # 示例
     ///
     /// ```
+    /// use minigrep_cli::Config; // 显式引入 Config 类型
     /// let args = vec!["program".to_string(), "query".to_string(), "file.txt".to_string()];
     /// let config = Config::build(args.into_iter());
     /// assert!(config.is_ok());