Save manifest when adding new song

xmpd-gui/src/windows/new_song.rs

@@ -111,7 +111,7 @@ impl Window for NewSongW {
                         s.set_name(&self.name);
                         s.set_author(&self.author); 
                         state.manifest.store_mut().get_songs_mut().insert(uuid::Uuid::new_v4(), s);
-                        
+                        let _ = state.manifest.save(); 
                         self.author = String::from("Unknown");
                         self.name = String::from("New Song");
                         self.source_t = SourceType::Youtube;