Update readme file regarding old exp and XDE tools (#2423)
Update readme file regarding old exp and XDE tools (#2423)

*  XDE has been replaced by Expo Dev Tools

https://blog.expo.io/expo-cli-2-0-released-a7a9c250e99c

* expo/expo-cli/s

exponentjs/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent,exponent/exponent,exponent/exponent,exponentjs/exponent,exponent/exponent,exponentjs/exponent,exponentjs/exponent