Loading from last checkpoint functionality in Trainer.train
Author: tanmay17061
Pull request: yes

Enhance resume_from_checkpoint argument of Trainer.train to accept
bool type. If True given, last saved checkpoint in self.args.output_dir
will be loaded. (#10280)

# What does this PR do?

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Please look at [the feature request](https://github.com/huggingface/transformers/issues/10280) for full description of the changes. Thanks.
Fixes #10280


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Comments:
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