mise a jour de l expo code example

Example 1: expo create react native app

npm install --global expo-cli

expo init my-project

Example 2: expo react native

/* Answer to: "expo react native" */

/*
  Expo is a toolchain built around React Native to help you quickly
  start an app. It provides a set of tools that simplify the
  development and testing of React Native app and arms you with the
  components of users interface and services that are usually
  available in third-party native React Native components.
  
  Find more information here:
  https://expo.io/
*/