Demo capturing screenshots in guides for .net mobile apps (#17035)

Resolves #4117
- #4117

## IS YOUR CHANGE URGENT?  

- [ ] None: Not urgent, can wait up to 1 week+

## SLA

cc: @Flash0ver 

## PRE-MERGE CHECKLIST

*Make sure you've checked the following before merging your changes:*

- [ ] Checked Vercel preview for correctness, including links
- [ ] PR was reviewed and approved by any necessary SMEs (subject matter
experts)
- [ ] PR was reviewed and approved by a member of the [Sentry docs
team](https://github.com/orgs/getsentry/teams/docs)

---------

Co-authored-by: J-P Nurmi <jpnurmi@gmail.com>

Author: jamescrosswell

docs/platforms/dotnet/guides/android/index.mdx

@@ -59,6 +59,11 @@ public class MainActivity : Activity
             // Native Android SDK options are available via options.Native
             options.Native.AnrEnabled = true;
 
+            // If your app doesn't have sensitive data, you can attach screenshots automatically when a Java/native
+            // error is captured.
+            // https://docs.sentry.io/platforms/android/configuration/options/#attachScreenshot
+            options.Native.AttachScreenshot = true;
+
             // Session Replay is currently available via the ExperimentalOptions
             options.Native.ExperimentalOptions.SessionReplay.OnErrorSampleRate = 1.0;
             options.Native.ExperimentalOptions.SessionReplay.SessionSampleRate = 1.0;

docs/platforms/dotnet/guides/apple/index.mdx

@@ -53,6 +53,10 @@ public class AppDelegate : UIApplicationDelegate
             // Native Apple SDK options are available via options.Native
             options.Native.EnableAppHangTracking = true;
 
+            // If your app doesn't have sensitive data, you can get screenshots on error events automatically
+            // https://docs.sentry.io/platforms/apple/guides/ios/configuration/options/#attachScreenshot
+            options.Native.AttachScreenshot = true;
+
             options.SetBeforeSend(evt =>
             {
                 if (evt.Exception?.Message.Contains("Something you don't care want logged?") ?? false)

docs/platforms/dotnet/guides/maui/index.mdx

@@ -73,6 +73,10 @@ public static MauiApp CreateMauiApp()
             options.TracesSampleRate = 1.0;
             // ___PRODUCT_OPTION_END___ performance
 
+            // If your app doesn't have sensitive data, you can get screenshots on error events automatically
+            // https://docs.sentry.io/platforms/dotnet/guides/maui/configuration/options/#AttachScreenshot
+            options.AttachScreenshot = true;
+
             // Other Sentry options can be set here.
         })