Added GROUP_ID and fixed permission error for configuration and wake data volumes

.env.example

@@ -11,6 +11,7 @@
 ### User ID:
 # This is used to set the correct permissions for the accessing the audio device and accessing the PulseAudio socket
 USER_ID="1000"
+USER_GROUP="1000"
 
 ### Name for the client (optional):
 # by default it uses the HOSTNAME variable from the piCompose environment which includes the MAC from the network card