Prepare release 0.6.4

Change-Id: I5f72c2fbf2a2ec86c108a47b4c854b069267276b
diff --git a/docs/releases.rst b/docs/releases.rst
index 5488f28..f47d556 100644
--- a/docs/releases.rst
+++ b/docs/releases.rst
@@ -5,6 +5,7 @@
    :hidden:
    :maxdepth: 1
 
+   release-notes/release-notes-0.6.4
    release-notes/release-notes-0.6.3
    release-notes/release-notes-0.6.2
    release-notes/release-notes-0.6.1
@@ -21,6 +22,12 @@
    release-notes/release-notes-0.2.0
    release-notes/release-notes-0.1.0
 
+* **NFD version 0.6.4**
+  (:doc:`Release Notes <release-notes/release-notes-0.6.4>`, `Documentation <https://named-data.net/doc/NFD/0.6.4/>`__)
+
+  `src (git) <https://github.com/named-data/NFD/releases/tag/NFD-0.6.4>`__,
+  `src (tarball) <https://named-data.net/downloads/nfd-0.6.4.tar.bz2>`__ (`checksum <https://named-data.net/downloads/nfd-0.6.4.tar.bz2.sha256>`__)
+
 * **NFD version 0.6.3**
   (:doc:`Release Notes <release-notes/release-notes-0.6.3>`, `Documentation <https://named-data.net/doc/NFD/0.6.3/>`__)