update webthings readme

Author: linomp

img/detected.PNG

@@ -4,8 +4,13 @@ This version of the arduino code exposes the functionality as a "Web Thing" usin
 
 ## How to test:
 
-See: [Docker image instructions](https://hub.docker.com/r/webthingsio/gateway)
+1. Install the open-source WebThings [Gateway Software](https://webthings.io/gateway/) on a Raspberry Pi (also available for Docker & Linux Desktop)
 
-```
-docker run -d  -p 8080:8080 -p 4443:4443 -e TZ=America/Los_Angeles -v /path/to/shared/data:/home/node/.webthings --log-opt max-size=1m --log-opt max-file=10 --name webthings-gateway webthingsio/gateway:latest
-```
+2. Flash and run the arduino code, then wait for the Gateway to detect it or manually type the device url that is shown in the Arduino IDE Serial Monitor
+
+    ![](../img/empty.PNG)
+    ![](../img/detected.PNG)
+
+3. Open the Logs section of the Webthings dashboard and add plots for the property values that you want to inspect (e.g. 'stationary', 'walking', etc.).  Change the view to 'Minutes' for near real-time visualization.
+
+    ![](../img/logs_tab.PNG)