feat: Clarify NYC-only dataset and add no results message

[roiyz]

This pull request is for improving the user experience for running restaurants finder example code by clarifying that it's just based on a local NYC restaurants dataset, as well as improving the results text when no restaurant is found. This also demonstrates how the llm model chooses a different renedring path when no results are found.

Verified both for positive and negative scenarios.

The new message to the user looks like the following: