Add details on differences between auto vs manual setup of Cocoa SDK

When configuring an iOS SDK, there are two options: `Auto` and `Manual`.

If choosing `Auto`, it summarizes the steps take like this:

> The Sentry wizard will automatically patch your application:
>
> - Install the Sentry SDK via Swift Package Manager or Cocoapods
> - Update your AppDelegate or SwiftUI App Initializer with the default Sentry configuration and an example error
> - Add a new Upload Debug Symbols phase to your xcodebuild build script
> - Create .sentryclirc with an auth token to upload debug symbols (this file is automatically added to .gitignore)
> - When you're using Fastlane, it will add a Sentry lane for uploading debug symbols

For the `Manual` setup we only mention the setup of the SDK and the verification example error.

I would like to discuss two points:

1. We should add a warning at the top indicating that the manual process **does not** cover all the steps taken by the wizard.
2. We should give the setup step for the uploading of debug symbols a more prominent location, i.e. before `Configure SDK` there should be a section "Setup Uploading Debug Symbols" which gives a summary of the purpose and benefits, with link to the user docs with relevant setup steps. This would keep the guide slim, while not making users skip the step all together.

cc @jas-kas @kahest

Locate the manual iOS/Cocoa SDK setup guide and compare it with the Auto setup steps listed in the issue. Add the warning and a prominent debug-symbol-upload section with a link to the relevant user documentation; done means the manual guide clearly covers the wizard’s omitted steps without duplicating the full setup.

Written by the indexing model from the issue text.