Docs should be clear that the example notebooks aren't standalone

The quickstart docs state _"You can also view a related code sample in a Jupyter notebook format, along with several other examples, in the [examples folder](https://github.com/microsoft/qdk-chemistry/blob/main/examples/) of the GitHub repository"_. I downloaded the extended_hubbard.ipynb notebook from there, and the sample data file it referenced, but it still took me a while to troubleshoot why I was getting the below. ```txt --------------------------------------------------------------------------- ModuleNotFoundError Traceback (most recent call last) Cell In[4], [line 1](vscode-notebook-cell:?execution_count=4&line=1) ----> [1](vscode-notebook-cell:?execution_count=4&line=1) from utils.viz_utils import generate_cube_data_with_info 2 3 # Identify orbitals from HOMO-2 to LUMO+2 4 hf_orbitals = wfn_hf.get_orbitals() ModuleNotFoundError: No module named 'utils' ``` After some digging I realized the notebooks are not standalone and depend on modules in the sibling `https://github.com/microsoft/qdk-chemistry/tree/main/examples/utils` dir from the repository. The docs should make this clearer.