Added documentation for Docker

Author: timchunght

README.md

@@ -78,6 +78,24 @@ If you want to require a username and password to access the dashboard, you can
 
 HTTPS and Basic Auth are mandatory if you are accessing the dashboard remotely instead of accessing it from `localhost`.
 
+## Run with Docker
+
+It is easy to use it with Docker. First build the image:
+  
+  docker build -t parse-dashboard .
+
+Run the image with your ``config.json`` mounted as a volume
+
+  docker run -d -p 8080:4040 -v host/path/to/config.json:/src/Parse-Dashboard/parse-dashboard-config.json parse-dashboard 
+
+The container will boot up using the default command ``npm run dashboard``
+
+However, you can run custom command as well (see ``Deploying in production`` for custom setup)
+
+  docker run -d -p 8080:4040 -v host/path/to/config.json:/src/Parse-Dashboard/parse-dashboard-config.json parse-dashboard npm start -- --allowInsecureHTTP=1
+
+If you are not familiar with Docker, ``npm start -- --allowInsecureHTTP=1`` is the custom command.
+
 ## Deploying in production
 
 If you're deploying to a provider like Heroku, or Google App Engine, the SSL endpoint is terminated early and handled by the provider and you may encounter this error `Parse Dashboard can only be remotely accessed via HTTPS`.