doc: reorganize files

Separate various autogen files from the documentation .dox files.
Rename .dox files to match the intended tree structure.

doc/examples/tutorial2.c

@@ -0,0 +1,56 @@
+/*
+  [title]
+  \ref page_tutorial2
+  [title]
+ */
+/* [code] */
+#include <pipewire/pipewire.h>
+
+static void registry_event_global(void *data, uint32_t id,
+		uint32_t permissions, const char *type, uint32_t version,
+		const struct spa_dict *props)
+{
+	printf("object: id:%u type:%s/%d\n", id, type, version);
+}
+
+static const struct pw_registry_events registry_events = {
+	PW_VERSION_REGISTRY_EVENTS,
+	.global = registry_event_global,
+};
+
+int main(int argc, char *argv[])
+{
+	struct pw_main_loop *loop;
+	struct pw_context *context;
+	struct pw_core *core;
+	struct pw_registry *registry;
+	struct spa_hook registry_listener;
+
+	pw_init(&argc, &argv);
+
+	loop = pw_main_loop_new(NULL /* properties */);
+	context = pw_context_new(pw_main_loop_get_loop(loop),
+			NULL /* properties */,
+			0 /* user_data size */);
+
+	core = pw_context_connect(context,
+			NULL /* properties */,
+			0 /* user_data size */);
+
+	registry = pw_core_get_registry(core, PW_VERSION_REGISTRY,
+			0 /* user_data size */);
+
+	spa_zero(registry_listener);
+	pw_registry_add_listener(registry, &registry_listener,
+				       &registry_events, NULL);
+
+	pw_main_loop_run(loop);
+
+	pw_proxy_destroy((struct pw_proxy*)registry);
+	pw_core_disconnect(core);
+	pw_context_destroy(context);
+	pw_main_loop_destroy(loop);
+
+	return 0;
+}
+/* [code] */