Update README.md

[vroomgit]

Fix broken link in README.md

Update broken link at [Using Amazon SageMaker Debugger with Your Own PyTorch Container] to (https://github.com/aws/amazon-sagemaker-examples/blob/main/sagemaker-debugger/pytorch_model_debugging/pytorch_script_change_smdebug.ipynb)

Description of changes:

Style and formatting:

I have run pre-commit install && pre-commit run --all-files to ensure that auto-formatting happens with every commit.

Issue number, if available

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.