Feat/incremental training

[aamantle-aws]

Description of changes: Added in OPTIONAL incremental training code, as referenced in the relevant blog post

Testing done: Notebook runs with added code as intended

Merge Checklist

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• I have read the CONTRIBUTING doc and adhered to the example notebook best practices
• I have updated any necessary documentation, including READMEs
• I have confirmed secret codes are not included in the example.
• I have tested my notebook(s) and ensured it runs end-to-end
• I have linted my notebook(s)

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