Remove double Elastic Search readme section in FluentD chart

## What

In the readme for the fluentd-kubernetes chart there are two sections for setting up forwarding to Elastic Search. The [first one](https://github.com/cloudposse/charts/tree/master/incubator/fluentd-kubernetes#read-k8s-logs-and-forward-to-elastic-search) is correct, the [second one](https://github.com/cloudposse/charts/tree/master/incubator/fluentd-kubernetes#read-k8s-logs-and-forward-to-elastic-search-1) is a copy of the datadog walkthrough above.

## Why

It's a duplicate of the wrong setup.