docs: update several URLs to point to docs.named-data.net

Change-Id: If000753573c6a50130dc3101a411b6d482ccf3ed
diff --git a/docs/release-notes/release-notes-0.8.1.rst b/docs/release-notes/release-notes-0.8.1.rst
index ccba1ca..a90a180 100644
--- a/docs/release-notes/release-notes-0.8.1.rst
+++ b/docs/release-notes/release-notes-0.8.1.rst
@@ -32,7 +32,7 @@
   (:issue:`5112`)
 
 - NFD management commands sent by :ndn-cxx:`nfd::Controller` now use the `new signed Interest
-  format <https://named-data.net/doc/NDN-packet-spec/0.3/signed-interest.html>`__ (:issue:`4804`)
+  format <https://docs.named-data.net/NDN-packet-spec/0.3/signed-interest.html>`__ (:issue:`4804`)
 
 Improvements and bug fixes
 ^^^^^^^^^^^^^^^^^^^^^^^^^^