Check external links and fix demonstration link

Change-Id: I330dbecd9b4049bd9d802d9bff2a49e4dfcc85c1
diff --git a/Makefile b/Makefile
index a084f5f..9d532a4 100644
--- a/Makefile
+++ b/Makefile
@@ -49,7 +49,7 @@
 	mdl -s $(LINT_STYLE) `find -L . ! -path "./partials/*" ! -path "./_book/*" ! -path "./repos/*"  ! -path "./node_modules/*" ! -path "./cord-tester/modules/*" -name "*.md"`
 
 linkcheck: $(ALL_DOCS) _book
-	linkchecker -a _book/
+	linkchecker -a --check-extern _book/
 
 # Host holding the git server
 REPO_HOST   ?= https://gerrit.opencord.org
diff --git a/operating_cord/rest_apis.md b/operating_cord/rest_apis.md
index 5f3f476..692aaa0 100644
--- a/operating_cord/rest_apis.md
+++ b/operating_cord/rest_apis.md
@@ -8,4 +8,4 @@
 
 You can access the REST API specification on a running POD by going to
 the `/apidocs/` URL on the Chameleon REST endpoint (exposed at
-port 30006 by default): <http://pod-ip-or-dns-address:30006/apidocs/>.
+port 30006 by default): `http://pod-ip-or-dns-address:30006/apidocs/`.