Adding more doxygen documentation
diff --git a/apps/ccnx-producer.h b/apps/ccnx-producer.h
index 55e7162..4b54d79 100644
--- a/apps/ccnx-producer.h
+++ b/apps/ccnx-producer.h
@@ -31,6 +31,14 @@
namespace ns3
{
+/**
+ * @brief A simple Interest-sink applia simple Interest-sink application
+ *
+ * A simple Interest-sink applia simple Interest-sink application,
+ * which replying every incoming Interest with Data packet with a specified
+ * size and name same as in Interest.cation, which replying every incoming Interest
+ * with Data packet with a specified size and name same as in Interest.
+ */
class CcnxProducer : public CcnxApp
{
public: