Adds sample code for code generation and understanding using Nova Pre…

[renatodossantosleal]

Adds code generation and understanding capabilities using Nova Premier.

Issue #, if available:

Description of changes:

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

[review-notebook-app[bot]]

Check out this pull request on 

See visual diffs & provide feedback on Jupyter Notebooks.

---

Powered by ReviewNB

[renatodossantosleal]

Just changed them to multimodal understanding.