Create develop-docs

Create develop docs similar to [https://github.com/getsentry/sentry-java/tree/main/develop-docs]() and [https://github.com/getsentry/sentry-cocoa/tree/main/develop-docs]()

Review the develop-docs directories in the linked sentry-java and sentry-cocoa repositories to identify their structure and coverage. Create an equivalent develop-docs area for sentry-react-native, with the relevant developer documentation adapted to this SDK; done means the directory and its planned contents are present and consistent with the reference projects.

Written by the indexing model from the issue text.