Add directory for API dependencies doc

Change-Id: Idb3f634a7b7a925be14c64102c7f76f1996da7fb
Issue-id: INT-11
Signed-off-by: Gary Wu <gary.i.wu@huawei.com>
diff --git a/documentation/api-dependencies/README.md b/documentation/api-dependencies/README.md
new file mode 100644
index 0000000..f82ddcf
--- /dev/null
+++ b/documentation/api-dependencies/README.md
@@ -0,0 +1,3 @@
+
+This directory contains the documentation for API dependencies between
+ONAP projects.