Add optf/cmso module in the readme docs

Change-Id: I28115c660a4d02d8a294ca81ec86ad8ae092edea
Signed-off-by: vrvarma <vv8305@att.com>
Issue-ID: OPTFRA-394
(cherry picked from commit d5b696a2fa09a5f6c5de87fbd61417897016bc12)
diff --git a/.gitmodules b/.gitmodules
index 2ad68f5..03073e8 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -346,3 +346,8 @@
 	url = ../dmaap/buscontroller
 	branch = .
 	ignore = dirty
+[submodule "docs/submodules/optf/cmso.git"]
+	path = docs/submodules/optf/cmso.git
+	url = ../optf/cmso
+	branch = .
+	ignore = dirty