reimplemented the result with errors

src/error.rs

@@ -0,0 +1,11 @@
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum YoutubeDLError {
+    #[error("failed to execute youtube-dl")]
+    IOError(#[from] std::io::Error),
+    #[error("failed to convert path")]
+    UTF8Error(#[from] std::string::FromUtf8Error),
+    #[error("youtube-dl exited with: {0}")]
+    Failure(String),
+}