Add details to README (#128)

* Initial beefing

* Update README.md

Author: gksander

README.md

@@ -1,8 +1,20 @@
-# react-native-owl
+# `react-native-owl`
+
+> Visual regression testing for React Native
+
+![Sample of using React Native Owl to generate a visual regression diff](https://raw.githubusercontent.com/FormidableLabs/react-native-owl/main/website/static/images/homepage/mockup-bg.png)
+
+---
 
 [![github][github-image]][github-url] [![npm][npm-image]][npm-url] [![docs][docs-image]][docs-url] [![Maintenance Status][maintenance-image]](#maintenance-status)
 
-> Visual regression testing for React Native
+## What is React Native Owl?
+
+React Native Owl is a visual regression testing library for React Native that enables developers to introduce visual regression tests to their apps for iOS and Android. Being heavily inspired by [Detox](https://github.com/wix/Detox), an end-to-end testing and automation framework, this library uses a similar API that makes setting up `react-native-owl` and running the tests locally and on your preferred CI service seamless.
+
+While Detox focuses on end-to-end testing in general, React Native Owl focuses on visual regression testing and helping you catch unexpected changes to the visual appearance of your app over time.
+
+### :rocket: [Check out the official documentation for more details!](https://formidable.com/open-source/react-native-owl/)
 
 ## Installation