Improved Sample app

## Feature request for Cloudinary React Native SDK
Improved Sample app

## Explain your use case
Need an improved sample app to demonstrates the SDK capabilities

## Describe the problem you’re trying to solve
Give developers an easy way to understand the SDK usage through a sample app

## Do you have a proposed solution?
Build an improved sample app

该 issue 未指定任何文件、测试或入口点。首先查看仓库现有的示例应用，以及它应该展示的 SDK 功能；完成的标准是有一个范围明确、经过改进的示例应用，使开发者能够轻松理解 SDK 的使用方式。

由索引模型根据 Issue 内容生成。