update readme

README.md

@@ -4,18 +4,33 @@ This project listens to evcc state updates via MQTT, to control the discharge of
 The powerwall is swichted between two "logical" modes BACKUP_ONLY and STANDBY (normal operations).
 To achieve this behavior the backup reserve percentage of the PW is controlled. BACKUP only mode
 simply means setting the reserve percentage to 100%, effectively preventing any discharge (unless grid fails).
-STANDBY mode is achieved by resetting the reserve percentage a configured default value of your installation.
+STANDBY mode is achieved by resetting the reserve percentage to a configured default value of your installation.
 Usually this value is configured via the slider in the Tesla App.
 
 ## decision logic 
-- as long as evcc is not in charging, put Powerwall in Standby
+- as long as evcc is not charging, put Powerwall in Standby
 - If evcc is charging, check the charge mode.
-- If charge mode is fast put PW into BACKUP only mode
+- If charge mode is fast put PW into BACKUP only mode.
 - Alternatively, if charge mode is PV and at the same time the planner is active, also put PW into BACKUP only mode  
 
 ## Limitations
 - only supports a single loadpoint
+- overwrites backup reserve percentages set via the Tesla App
 
-## configuration
+## Configuration
 You need to create a configuration, an example template can be found in the `config` folder.
-At a minimum you need to adjust the mqtt broker's url, and you need to provide an oauth refresh token for your Tesla account.
+At a minimum you need to adjust the `mqtt.broker.url`, and you need to provide an oauth refresh token for your Tesla account (in `tesla.refreshToken`).
+Optionally, you may also want to adjust the `tesla.backupReservePercent` to match your current settings in the Tesla App.
+The configuration file needs to be mounted into the container as `/usr/src/app/config/default.json`.
+
+## Running
+The docker image can be used in a compose file (e.g. together with evcc) as shown below.
+
+```
+  evcc-mqtt-listener:
+    container_name: evcc-mqtt-listener
+    image: ghcr.io/grimmimeloni/evcc-mqtt-listener:main
+    volumes:
+      - ./evcc-mqtt-config/default.json:/usr/src/app/config/default.json
+    restart: unless-stopped
+```