Fix typing annotations for FSDP and DeepSpeed in TrainingArguments
# What does this PR do?
According to the the docstrings and to the code, options `fsdp_config` and `deepspeed` of `TrainingArguments` accept dictionaries with configs for FSDP and DeepSpeed correspondingly. However, the typing annotations for both of them mention only `str` as valid arguments, which makes typing checkers fail when trying to pass a dictionary for these options.

This PR fixes the problem by making these options accept `Dict` as well, also fixing a couple of minor typos in their descriptions.

## Before submitting
- [x] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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      Pull Request section?
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      to it if that's the case.
- [ ] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/main/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/main/docs#writing-source-documentation).
- [ ] Did you write any new necessary tests?

@sgugger 
_The documentation is not available anymore as the PR was closed or merged._<|||||> argument --deepspeed: invalid Dict value: './ds_config_zero3.json' i am face this after merge, i have change deepspeed to Optional[str] and it worked <|||||>Ok, let's revert then as it's a purely cosmetic change.