Added installation notes

README.md

@@ -8,4 +8,13 @@ This addon was inspired by the [Wunderground Update Receiver Binding](https://ww
 
 The addon acts as a receiver for Personal Weather Stations (WH9000) and publishes the received updates to an MQTT topic, as well as on to [Wunderground.com](https://Wunderground.com).
 
+## Installation
 
+Add this URL to your HAAS add-on repositories:
+
+https://github.com/peterzen/haas-pws-mqtt-addon
+
+
+## Configuration
+
+There is really only one configuration option, `mqtt_topic` that specifies the MQTT topic the data is to be pushed to.  The addon talks to the default MQTT service configured in HASS.