docs: Update documentation and Doxygen documentation generation
diff --git a/utils/tracers/ipv4-l3-tracer.h b/utils/tracers/ipv4-l3-tracer.h
index 2e08054..b63dc01 100644
--- a/utils/tracers/ipv4-l3-tracer.h
+++ b/utils/tracers/ipv4-l3-tracer.h
@@ -29,6 +29,10 @@
 
 class Node;
 
+/**
+ * @ingroup ndn-tracers
+ * @brief Base class for IPv4 network-layer tracers
+ */
 class Ipv4L3Tracer : public SimpleRefCount<Ipv4L3Tracer>
 {
 public: