SpotifyRecorder: check for valid start number

SpotifyRecorder.py

@@ -40,7 +40,11 @@ class SpotifyRecorder:
         self._spotifyDeviceName = spotifyDeviceName
         self._audioDeviceName = audioDeviceName
         self._destinationFolder = destinationFolder
+
+        if startNumber <= 0:
+            raise ValueError(f'startNumber must be greater than 0')
         self._startNumber = startNumber
+
         self._limit = limit
 
         os.makedirs(self._destinationFolder, exist_ok=True)