Create a "one-pager" for running Elasticsearch and Kibana in Docker w Security Enabled

[debadair]

"Specifically looking for getting started instruction smoothness for Docker." (@derickson)

[debadair]

After discussing with @jethr0null, getting some more background from @derickson, and looking at our existing docs, Docker Hub image readmes, Open Distro docs, third party tutorials, and forum threads, there are a few key issues:

• Nowhere do we officially document how to run ES and Kibana in Docker containers and get them talking to one another. (https://discuss.elastic.co/t/kibana-docker-image-doesnt-connect-to-elasticsearch-image/79511)
• The instructions for running with Docker aren't consistent. For example, we talk about running ES with Docker Compose, but we don't provide a sample compose file for Kibana.
• Our sample compose file starts two ES instances. That seems like a pattern that we probably don't want to encourage, especially in a section titled "Production Mode".
• You have to click around to get to the info about enabling security.

We might be able to repurpose some of the instructions @jethr0null wrote for the Docker Hub image readmes. The Discuss thread & referenced issue have info about getting Kibana and ES talking to one another.

I'm also going to follow up with @woodywalton, who has been looking at collecting this information in the context that prompted the ask.