feat(native): external crash reporter (#15244)

Author: jpnurmi

docs/platforms/native/advanced-usage/external-crash-reporter/img/sentry-desktop-crash-reporter.png

@@ -0,0 +1,30 @@
+---
+title: External Crash Reporter
+description: "How to configure an external crash reporter with the Native SDK."
+sidebar_order: 2100
+---
+The Native SDK can be configured to work with an external crash reporter, which
+can be used to display crash information to the user, collect user feedback, or
+perform other actions when a crash occurs.
+
+The external crash reporter is a user-defined executable, distinct from the
+system crash reporter, that is launched by the Native SDK upon a crash. It
+receives the path to the crash report as its only command-line argument and
+is responsible for submitting the crash report to Sentry.
+
+[Sentry Desktop Crash Reporter](https://github.com/getsentry/sentry-desktop-crash-reporter)
+is a ready-made crash reporter reference implementation. It is a cross-platform
+desktop application made with [.NET](https://dot.net) and [Uno Platform](https://platform.uno/).
+
+![Sentry Desktop Crash Reporter](./img/sentry-desktop-crash-reporter.png)
+
+To configure the Native SDK to use an external crash reporter, set the
+`external_crash_reporter_path` option to the path of the external crash reporter
+executable when initializing the SDK:
+
+```c
+sentry_options_t *options = sentry_options_new();
+sentry_options_set_external_crash_reporter_path(options, "/path/to/external_crash_reporter");
+/* ... */
+sentry_init(options);
+```