Update getting_started.rst (#1188)
Update getting_started.rst (#1188)

Summary:
Hi,

I think there is a minor mistake in the doc. `--distributed-no-spawn` argument is needed for distributed training on multiple machines without `slurm`. Otherwise, the program will start 8 jobs on each GPU, when `nproc_per_node=8`.
Pull Request resolved: https://github.com/pytorch/fairseq/pull/1188

Differential Revision: D17627778

Pulled By: myleott

fbshipit-source-id: 35ab6b650dc1132d7cb2d150e80d2ebf0caf3e69

pytorch/fairseq,pytorch/fairseq,pytorch/fairseq