Add battery level, fix LSB to voltage

serial_to_mqtt_bridge/config.yaml

 mqtt:
-  broker: "mosquitto"
+  broker: "localhost"
   port: 1883
   topic: "serial2MQTT"
 
@@ -8,4 +8,4 @@ serial:
 
 sim:
   interval: 1  # Interval in seconds for reading lines from the file
-  file_path: "sim_data.txt"
\ No newline at end of file
+  file_path: "sim_data.txt"