message: add ngc to readme
diff: @@ -20,6 +20,15 @@ This document describes how to set up the environment and run HugeCTR.
  For more details such as HugeCTR architecture and supported features, please refer to [**HugeCTR User Guide**](docs/hugectr_user_guide.md) and [**Questions and Answers**](docs/QAList.md) in directory `docs/`
  ## Quick Start
  +A production docker image of HugeCTR is available in the NVIDIA container repository at the following location: https://ngc.nvidia.com/catalog/containers/nvidia:hugectr.
  +You can pull and launch the container using the following command:
  +```shell
  +docker run --runtime=nvidia --rm -it -u $(id -u):$(id -g) nvcr.io/nvidia/hugectr:v2.2.1 bash
  +```
  +If you are running on a docker version 19+, change `--runtime=nvidia` to `--gpus all`.
  +
  +This container is used for production scenarios, so it only contains the necessary executable files for generating a synthetic dataset or training a model. For a complete installation, please refer to the following steps.
  +
  ### 1. Download Repository ###
  You can download the HugeCTR repository and the third party modules which it relies upon:
  ```shell
  