Add notebook example support for each package

[gaudyb]

Description

Add multiple example notebooks to each package for better user support.

Checklist

• I have tested these changes locally.
• I have reviewed the code changes.
• I have updated the documentation (if necessary).
• I have added appropriate unit tests (if applicable).

[dworthen]

Hi @gaudyb, Looks like the notebooks for graphrag_llm were moved to example_notebooks. Can you update tests/notebook/test_notebooks.py with the new location? It appears the test is currently passing when there are no notebooks to test. Can you update the test so that an error is thrown if notebooks_list is empty so that we don't have false positives when the tests don't run anything.