Add example program invocation to readme

README.md

@@ -3,6 +3,18 @@
 Uses a convolutional neural network to recognize the position of pieces
 on a chessboard image.
 
+If you have an image of a chessboard in `chessboard.png`
+
+<img src="https://user-images.githubusercontent.com/208617/69907303-d526b400-13a0-11ea-982f-47dc7cacecdc.png" width=320 />
+
+Run the program like this
+
+`./recognize.py chessboard.png`
+
+To get the chessboard position in [FEN](https://en.wikipedia.org/wiki/Forsyth%E2%80%93Edwards_Notation) notation
+
+`111rkb1r/1pp11ppp/11n1q1n1/p111Pb11/11Pp1111/PN111NB1/1P1QPPPP/111RKB1R`
+
 ## Getting started
 
 Training and using the neural network requires [Tensorflow 2](https://www.tensorflow.org/)