[Feature Request] Examples for yfpy.util functions

## Description
Documentation update: add example codeblocks for yfpy.utils functions similar to yfpy.query... guides

## Use case
Novice python user accessibility for handling complex nested dict/list/JSON structures.

---
This package is excellent and has allowed us novices to query the complex Yahoo API. Now just wondering if you can help us understand the utility functions. 

Thank you