No Network security group defined in docker-simple-on-ubuntu quickstart template

[docker-simple-on-ubuntu] https://github.com/Azure/azure-quickstart-templates/tree/052db5feeba11f85d57f170d8202123511f72044/docker-simple-on-ubuntu

### Issue Details
No Network security group defined in docker-simple-on-ubuntu. Seems to be something that would be obvious in this day of security threats. I understand these are example quickstarts, but excluding a network security group from the template seems rather irresponsible.

A better approach would be to include a network security group that only allows SSH for the intial deployment and documentation in the readme about how/why to update.

Start by reviewing the docker-simple-on-ubuntu quickstart template at the linked revision and its README to understand the current network configuration. Add a network security group that permits SSH for the initial deployment, and document in the README how and why it should be updated.

Written by the indexing model from the issue text.