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

Change-Id: I4bab897f17e2b929675119198c9eab0309b6cc3e
diff --git a/CITATION.cff b/CITATION.cff
index 623178d..dbcae28 100644
--- a/CITATION.cff
+++ b/CITATION.cff
@@ -3,7 +3,7 @@
 license: GPL-3.0-or-later
 repository-code: "https://github.com/named-data/NFD"
 title: Named Data Networking Forwarding Daemon
-url: "https://named-data.net/doc/NFD/"
+url: "https://docs.named-data.net/NFD/"
 preferred-citation:
   authors:
     - name: Named Data Networking Project Team