docs: Add Requirements

ChenYuan · web-flow · commit b8e77af66379 · 2017-02-18T13:59:39.000+08:00
saving time for look up how to install the "cv2" package
diff --git a/webcam.py b/webcam.py
@@ -1,3 +1,7 @@
+# Requirements:
+#     pip install numpy
+#     sudo apt-get install python-openCV
+
 import numpy as np
 import cv2
 
