Update README to reflect Expo integration support

[brentvatne]

Hello! It looks like now you provide a way to integrate with Expo, so this design principle doesn't appear to apply anymore.

[alidcast]

It seems like expo managed workflow wouldn't work due to the react-native-tcp-socket dependency used for the repl

edit: looks like it works with custom development builds

[swannodette]

Ah sorry looked I addressed this some time ago.