Added parametrization of workers.

Change-Id: I657f405843b944ae88bd1bb95b4efbeebacde12f
diff --git a/README.rst b/README.rst
index 32fbf92..a2367bb 100644
--- a/README.rst
+++ b/README.rst
@@ -34,6 +34,7 @@
       server:
         enabled: true
         version: juno
+        workers: 8
         policy:
           publicize_image:
             - "role:admin"