docs: delete certificate spec
Moved to the NDN-packet-spec repo
https://github.com/named-data/NDN-packet-spec/commit/3a74e134979606af9a2b90b12f141f8794ad96d7
Change-Id: I57aec08aeb553d5eb6c5a7c368ba03b904b1e4ed
diff --git a/docs/release-notes/release-notes-0.5.1.rst b/docs/release-notes/release-notes-0.5.1.rst
index 033a6bd..455a19a 100644
--- a/docs/release-notes/release-notes-0.5.1.rst
+++ b/docs/release-notes/release-notes-0.5.1.rst
@@ -13,10 +13,11 @@
New features
^^^^^^^^^^^^
-- Add version 2 of the security framework (introduced in ``security::v2`` namespace)
+- Add version 2 of the security framework in ``security::v2`` namespace
- * :doc:`/specs/certificate` (:issue:`3103`)
- * New Public Information Base (PIB) and Trusted Program Module (TPM) framework to manage
+ * `NDN Certificate Format version 2.0
+ <https://named-data.net/doc/NDN-packet-spec/0.3/certificate.html>`__ (:issue:`3103`)
+ * New Public Information Base (PIB) and Trusted Platform Module (TPM) framework to manage
public/private keys and NDN Certificate version 2.0 (:issue:`2948`, :issue:`3202`)
* New KeyChain implementation (:issue:`2926`)
* New Validator implementation (:issue:`3289`, :issue:`1872`)