mpegtsmux: add SECTION comment

We include an example for injecting sections in the transport
stream in the documentation

docs/meson.build

@@ -179,5 +179,6 @@ foreach plugin_name: list_plugin_res.stdout().split(':')
         gst_c_source_filters: excludes,
         gst_order_generated_subpages: true,
         gst_plugin_name: plugin_name,
+        include_paths: join_paths(meson.current_source_dir(), '..'),
     )]
 endforeach

gst/mpegtsmux/gstmpegtsmux.c

@@ -82,6 +82,17 @@
  *
  */
 
+/**
+ * SECTION: element-mpegtsmux
+ * @title: MPEG Transport Stream muxer
+ *
+ * mpegtsmux muxes different streams into an MPEG Transport stream
+ *
+ * SI sections can be specified through a custom event:
+ *
+ * {{ tests/examples/mpegts/ts-section-writer.c }}
+ */
+
 #include "gstmpegtsmux.h"
 #include <string.h>