Add Nokia SVNFM driver documentation

Change-Id: I8b92b024908400d947e1ef896432561098b9a2bc
Signed-off-by: Denes Nemeth <denes.nemeth@nokia.com>
Issue-ID: VFC-728
diff --git a/.gitmodules b/.gitmodules
index 93aec56..d3c0b83 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -287,3 +287,6 @@
 [submodule "docs/submodules/dmaap/dbcapi.git"]
 	path = docs/submodules/dmaap/dbcapi.git
 	url = ../dmaap/dbcapi
+[submodule "docs/submodules/vfc/svnfm.git"]
+	path = docs/submodules/vfc/svnfm.git
+	url = ../vfc/nfvo/driver/vnfm/svnfm