Add RN specific options to the docs

[bruno-garcia]

i.e: https://github.com/getsentry/sentry-react-native/blob/c1a01ec67a2f10db16c3c67a866fc5839702063b/src/js/backend.ts#L16-L36

[github-actions]

This issue has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you label it Status: Accepted, I will leave it alone ... forever!

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"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀