fix(apple): Not taking screenshots for all crashes

Explain why the Cocoa SDK can't capture screenshots for all types of
crashes.

Author: philipphofmann

docs/platforms/apple/common/enriching-events/screenshots/index.mdx

@@ -10,7 +10,7 @@ notSupported:
   - apple.watchos
 ---
 
-Sentry makes it possible to automatically take a screenshot and include it as an <PlatformLink to="/enriching-events/attachments/">attachment</PlatformLink> when a user experiences an error, an exception or a crash.
+Sentry makes it possible to automatically take a screenshot and include it as an <PlatformLink to="/enriching-events/attachments/">attachment</PlatformLink> when a user experiences an error, an exception or a crash. When a crash occurs on Apple operating systems, there is no guarantee that the Cocoa SDK can still capture a screenshot because, strictly speaking, you're not allowed to call any async unsafe code. Still, it works in most cases, but we can't guarantee screenshots for all types of crashes.
 
 This feature is only available for SDKs with a user interface, like the ones for mobile and desktop applications. It's also limited by whether taking a screenshot is possible or not. For example, in some environments, like native iOS, taking a screenshot requires the UI thread, which often isn't available in the event of a crash. Another example where a screenshot might not be available is when the event happens before the screen starts to load. So inherently, this feature is a best effort solution.