tools: alias 'nfdc cs' to 'nfdc cs info'

Change-Id: Ied1d34a84110ee0b6488d35d56fb1caecaf14117
Refs: #4498
diff --git a/docs/manpages/nfdc-cs.rst b/docs/manpages/nfdc-cs.rst
index cef31b8..4ff387c 100644
--- a/docs/manpages/nfdc-cs.rst
+++ b/docs/manpages/nfdc-cs.rst
@@ -3,7 +3,7 @@
 
 SYNOPSIS
 --------
-| nfdc cs info
+| nfdc cs [info]
 
 DESCRIPTION
 -----------