Make dedicated pyproject.toml for the example notebooks #92

Currently, examples\notebooks depend on the venv created with the root package. It would be cleaner if we had a separate pyproject.toml to use for each notebook. This would remove dependencies in the root pyproject.toml that are only needed for notebooks (if any). It would also remove all of the dev dependencies from the notebooks' venv(s) so those would be cleaner.

It may be possible to have a single venv for all of the notebooks. However, this would mean it's pyproject.toml would show all the deps for all notebooks. Consider / discuss this when fixing this issue.

AB#3744853