message: add Note to main ReadMe
diff: @@ -41,6 +41,11 @@ If you'd like to quickly train a model using the Python interface, do the follow
  **NOTE**: The **/your/host/dir** directory is just as visible as the **/your/container/dir** directory. The **/your/host/dir** directory is also your starting directory.
  + **NOTE**: HugeCTR uses NCCL to share data between ranks, and NCCL may requires shared memory for IPC and pinned (page-locked) system memory resources. It is recommended that you increase these resources by issuing the following options in the `docker run` command.
  + ```text
  + -shm-size=1g -ulimit memlock=-1
  + ```
  +
  2. Write a simple Python script to generate a synthetic dataset:
  ```
  # dcn_norm_generate.py
  