Rebuilt /example fixes #940

[ironicbrew]

Large diff but only one file (README.md) outside of the /example directory has been altered and now uses a relative repo link. Most file changes are a side effect of initing a new react-native app in /example.

• Previous version of App.js remains largely the same minus some code cleanup and improved UI/UX.
• Fixed state management issue/state overlap(ie. peripherals and peripheralList)
• Use of Map() was outside of a useState causing rerender issues
• Connected devices now display their state automatically
• Added example/README.md with standalone instructions
• Import of react-native-ble-manager changed from relative import to standalone npm module as I think this brings the example more in line with being truely standalone.
• Removed pizza example

Note: I don't currently have a working Android device so I wasn't able to test this on Android beyond using a simulator.

Happy to tweak as needed, just let me know.

Cheers!

[ironicbrew]

[marcosinigaglia]

Thanks