updated readme.

Author: farrukh

Diff for: README.md

@@ -4,4 +4,5 @@ Also added ultrasonic sensor.
 OTA also added,
 simply open this link to update firmware if needed after first load, 
 http://192.168.4.1/update
-there may be few extra header files in code, you can remove yourself.
+there may be few extra header files in code, you can remove yourself.
+Demo: https://www.youtube.com/watch?v=sfO7whYDyD8