Add option to deny access for group

PROD-31381

Change-Id: I0fbe2a972661ad889a10aba0978a8fed558ff836
diff --git a/README.rst b/README.rst
index 536a4d5..23454d9 100644
--- a/README.rst
+++ b/README.rst
@@ -172,6 +172,10 @@
           test_salt_project:
             enabled: true
             access:
+              "refs/*":
+                - name: read
+                  group: Anonymous Users
+                  deny: true
               "refs/heads/*":
                 actions:
                 - name: abandon