update react-native install documentation

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Description

What do you expect to see or happen. What happens instead?

update react-native docs, to install

yan add @sentry/react-native npm install @sentry/react-native --save

import Sentry from '@sentry/react-native';

Proposed Solution(s)

What do you think should be changed? This could be a code change or a documentation change. Are you interested in doing this change yourself? Do you need assistance getting up to speed on how to develop for GlitchTip?

What do you think should be changed? Update documentation

Are you interested in doing this change yourself? Sure

Do you need assistance getting up to speed on how to develop for GlitchTip? Yes