Update README.md

[shawn-fetanat]

So I noticed the other day when someone in the r/ReactNative subreddit asked what this library does that people were still confused about it's purpose even after reading the docs. When I cleared up their confusion, they thanked me and suggested I submit a PR so I figured why not. If you don't like my changes you can always reject it and/or ask me to change it to your liking lol. I know you said to let you know what we're aiming to do. I hope I was clear enough but in case I wasn't. My aim to make it more clear to people what the purpose of this library is and the benefits of using it because people are clearly confused after reading this README.

I just made a few changes based on what it seemed like people were mostly confused about and tried to organize and clean it up a bit.

I know you can easily see my additions and changes in the diff but here's specifically what I updated:

Updated Sections

• Purpose
• Storage Engines

Added Sections

• Features
• Installation

Additional Changes

• Fixed broken link to config object in API to config