Code reorganizing (#17)

Reviewed-on: #17
Co-authored-by: phoenix <kundeng00@pm.me>
Co-committed-by: phoenix <kundeng00@pm.me>

src/types.rs

@@ -0,0 +1,8 @@
+pub enum Type {
+    Title,
+    Artist,
+    Album,
+    Genre,
+    Date,
+    Track,
+}