Add note about dockerfile addition

Author: kraigb

README.md

@@ -1,5 +1,7 @@
 This sample contains the completed program from the tutorial, [Using Django in Visual Studio Code](https://code.visualstudio.com/docs/python/tutorial-django). Intermediate steps are not included.
 
+The sample also includes a Dockerfile to build a production-ready container image that uses uwsgi and nginx; the uwsgi.ini file provides uwsgi configuration.
+
 To run the sample:
 
 1. Create a virtual environment as described in the tutorial.