docs: Updating documentation for 0.1.0 release

Change-Id: I1834a8a2ba9a9c7059517e3dbd784a377b0457bd
Refs: #1583
diff --git a/docs/RELEASE_NOTES.rst b/docs/RELEASE_NOTES.rst
index 886ca98..b6113af 100644
--- a/docs/RELEASE_NOTES.rst
+++ b/docs/RELEASE_NOTES.rst
@@ -1,7 +1,7 @@
 .. _ndn-cxx v0.1.0 Release Notes:
 
 ndn-cxx v0.1.0 Release Notes
-============================
+----------------------------
 
 Version 0.1.0 is the initial release of ndn-cxx, an NDN C++ library with eXperimental
 eXtensions.