docs: update iOS auto-linking docs after adding support for PNPM and workspace setups

[felipebrahm]

Summary:

The react-native project updated how the auto-linking script is imported into the Podfile (facebook/react-native#36485), so we need to update the docs to reflect these changes.

Checklist

• Documentation is up to date to reflect these changes.
• Follows commit message convention described in CONTRIBUTING.md

[thymikee]

Thanks!