docs: Update documentation and Doxygen documentation generation
diff --git a/utils/tracers/l2-tracer.h b/utils/tracers/l2-tracer.h
index a937d66..e6378b5 100644
--- a/utils/tracers/l2-tracer.h
+++ b/utils/tracers/l2-tracer.h
@@ -29,6 +29,12 @@
 
 class Node;
 
+/**
+ * @ingroup ndn-tracers
+ * @brief Link-layer tracer
+ *
+ * @todo Finish implementation
+ */
 class L2Tracer : public SimpleRefCount<L2Tracer>
 {
 public: