update example config

.env.example

-MQTT_SERVER_ENABLED=false
+MQTT_SERVER_ENABLED=true
 MQTT_LISTEN=0.0.0.0:1883 # only required for MQTT server
-MQTT_HOST=1.2.3.4
+MQTT_HOST=127.0.0.1
 MQTT_PORT=1883
 MQTT_USERNAME=mqtt
-MQTT_PASSWORD=password
+MQTT_PASSWORD=mqtt
 MQTT_TOPIC_BOILER=ems-esp/boiler_data
+
 LOG_LEVEL=INFO
+
 OUTPUT_FILE_NAME="boiler.csv"
 OUTPUT_FILE_NAME_RAW="boiler.txt"
-ZEROMQ_BIND="tcp://127.0.0.1:5557"
+
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+QUEUE_STATE_FOLDER="./queues"
+
+OUTPUT_DATABSE=ems_esp_logger
+OUTPUT_DATABASE_USER=root
+OUTPUT_DATABASE_PASSWORD=password
+OUTPUT_DATABASE_HOST=localhost
+OUTPUT_DATABASE_TYPE=mysql
+OUTPUT_DATABASE_EXECUTE_MIGRATIONS=true
+
+INSTANCE_NAME=test
+INSTANCE_DESCRIPTION="My test instance"
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