refer to vndr wrapper for adding new packages, and godep for restoring

Author: yangkev

CONTRIBUTING.md

@@ -23,4 +23,6 @@ Follow either of the two links above to access the appropriate CLA and instructi
 
 ### Adding dependencies
 
-If your patch depends on new packages, add that package with [`vndr`](https://github.com/LK4D4/vndr). Refer to the Kubernetes Community [documentation](https://github.com/kubernetes/community/blob/master/contributors/devel/sig-architecture/godep.md) on dependency management for general best practices.
+If your patch depends on new packages, add that package using the provided [hack/update-vendor.sh](cri-tools/hack/update-vendor.sh) script, which is a wrapper around [vndr](https://github.com/LK4D4/vndr).
+
+To restore package versions with `godep`, refer to the Kubernetes Community docs for [restoring dependencies](https://github.com/kubernetes/community/blob/master/contributors/devel/sig-architecture/godep.md#restoring-deps).