fix:修改 helloword 错误

data/2.Go语言中阶/1.九阴真经/2.切片/slice.md

@@ -9,7 +9,7 @@ func main() {
     s = append(s, 4)
 
     fmt.Println(a, len(a), cap(a))
-    fmt.Println(s, len(s), cap(s)) // 输出：[888 2 3 4] 4 6
+    fmt.Println(s, len(s), cap(s))
 }
 ```