docs: Update documentation and Doxygen documentation generation
diff --git a/utils/tracers/ndn-cs-tracer.h b/utils/tracers/ndn-cs-tracer.h
index 87c290e..906e85a 100644
--- a/utils/tracers/ndn-cs-tracer.h
+++ b/utils/tracers/ndn-cs-tracer.h
@@ -48,6 +48,7 @@
 
 namespace cs {
 
+/// @cond include_hidden
 struct Stats
 {
   inline void Reset ()
@@ -58,11 +59,12 @@
   double m_cacheHits;
   double m_cacheMisses;
 };
+/// @endcond
 
 }  
 
 /**
- * @ingroup ndn
+ * @ingroup ndn-tracers
  * @brief NDN tracer for cache performance (hits and misses)
  */
 class CsTracer : public SimpleRefCount<CsTracer>