Document how to disable RuntimeMarshalManagedExceptionCapture (#14102)

Resolves getsentry/sentry-dotnet#4266

Author: jamescrosswell

docs/platforms/dotnet/common/configuration/disable-integrations.mdx

@@ -22,6 +22,12 @@ options.DisableAppDomainUnhandledExceptionCapture()
 
 Disables automatic capture of unhandled exceptions.
 
+## DisableRuntimeMarshalManagedExceptionCapture
+
+Disables automatic capture of unhandled exceptions on iOS.
+
+The `AppDomainUnhandledException` handler does [not reliably capture unhandled exceptions on iOS](https://github.com/getsentry/sentry-dotnet/pull/3909). Instead, `Runtime.MarshalManagedException` is used to capture unhandled exceptions on iOS.
+
 ## DisableUnobservedTaskExceptionCapture
 
 Disables automatic capture of Unobserved Task Exceptions.