Add Documentation for Adding Error Callbacks and Error Handling to an RNW App Blank in Release.

[chiaramooney]

Gallery recently hit the familiar issue where an RNW app renders correctly in Debug, but blank in Release. When discussing how we could improve the debugging experience Create a document on how to add error callbacks and error handling to an RNW app blank in release to give the developer more information on the cause of the issue.

[chrisglein]

Some documentation exists: https://microsoft.github.io/react-native-windows/docs/native-api/IRedBoxHandler What is missing is guidance on how you might use it as an app author to get to your errors faster.