Update README.md

Author: dala318

README.md

@@ -3,3 +3,17 @@
 With a lot of inspiration and help from https://github.com/Apollon77/node-ph803w project I ported the basic functionallity to python with the hope and expectation to deploy it as an Home Assistant intagration without need for a docker service and MQTT.
 Still a lot left to do but at least it can poll the device and show values in Home Assistant.
 In desktop mode (running cyclic with lib/main.py) it performs a bit better.
+
+## Installation of HA component
+
+1. Clone this repo as `ph803w` dir into `$HA_CONFIG_DIR/custom_components/`:
+   ```
+   $ cd custom_components
+   $ git clone git@github.com:dala318/ph803w.git ./ph803w
+   ```
+2. Setup `$HA_CONFIG_DIR/configuration.yaml`:
+
+```yaml
+ph803w:
+  host: 192.168.1.2    # IP of your gateway
+```