Add note that the primary Gerrit is not scalable yet

Change-Id: Ie67e27df081d7a08f72a51a26a0af39da7cc8f13
diff --git a/helm-charts/gerrit/README.md b/helm-charts/gerrit/README.md
index 4aa9b8a..4b0ba8a 100644
--- a/helm-charts/gerrit/README.md
+++ b/helm-charts/gerrit/README.md
@@ -225,6 +225,13 @@
 is mandatory, if access to Gerrit is required!
 ***
 
+***note
+While the chart allows to configure multiple replica for the Gerrit StatefulSet,
+scaling of Gerrit is currently not supported, since no mechanism to guarantee a
+consistent state is currently in place. This is planned to be implemented in the
+future.
+***
+
 | Parameter                              | Description                                                                                         | Default                                                                                  |
 |----------------------------------------|-----------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------|
 | `gerrit.images.gerritInit`             | Image name of the Gerrit init container image                                                       | `k8s-gerrit/gerrit-init`                                                                 |