Added `len` method to `Creator`

src/creator/mod.rs

@@ -44,6 +44,10 @@ impl Creator {
         })
     }
 
+    pub fn len(&self) -> usize {
+        self.entries.len()
+    }
+
     pub fn create(self, outdir: &Path, sender: Sender<Message>) -> Result<(), Box<dyn Error>> {
         let d = env::current_dir()?;
         let plist = Mutex::new(Plist::default());