specify config file path on README

[kwonmha]

I had hard time figuring out how to run on multi-node configuration with the given instructions.
It looked like no configuration file argument is required and accelerate will find the generated configuration automatically.
Just few more phrases are needed.

@muellerzr , @pacman100

[muellerzr]

Good idea, just needs some tweaks. Let's change this to have accelerate config explicitly save it to a location if we want to do so. Otherwise the latter command should be modified to show where the config coming from. These commands need to be ran quickly via copy/paste for new users. So let's go with my suggestion here and propagate it below :)

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint.

[kwonmha]

Good suggestion. I applied your suggestion to all proper positions.

Though it is minor issue, I'm not sure what form of the second command you wanted to be.
Because you said these commands should be run via copy/paste so I changed the second one like this to minimize modification by users.
accelerate launch --config_file config.yaml ./cv_example.py --data_dir path_to_data

But it already has --data_dir path_to_data which needs to be modified by users so the previous version was like this.
accelerate launch --config_file generated_config_file ./cv_example.py --data_dir path_to_data

[muellerzr]

@kwonmha the data_dir path is fine, we care about everything up-to the arguments being passed to file

[muellerzr]

Thanks!