doc

README.md

@@ -1,5 +1,13 @@
 # Solar Controller
 
+## System commands
+
+### 1. Enable heating
+
+```sh
+echo -n '{"command": "set-parameter", "args": { "name": "heating_enabled", "value": 1}}' | pub -broker ssl://mqtt.broker.name:443 -topic 'solar-controller/command' -username solar-controller -password secret -qos 1
+```
+
 ## License
 
 MIT