Fix balltracking readme

Author: hannesa2

ball_track/README

@@ -0,0 +1,9 @@
+# Ball Track Example
+
+Note: This Example is still in progress, notthing sure happens. If you are interested, give it a try.
+
+## Start 
+
+To run `python3 ball_tracker.py` first, you need to install cv2 first
+
+`sudo apt-get install python3-opencv`