Update rabbitmq helm chart for RabbitMQ 3.9.1 (#540)

charts/rabbitmq/Chart.yaml

@@ -7,6 +7,6 @@ type: application
 maintainers:
   - name: groundhog2k
 
-version: 0.3.0
+version: 0.3.1
 
-appVersion: "3.9.0"
+appVersion: "3.9.1"

charts/rabbitmq/README.md

 # RabbitMQ
 
-![Version: 0.3.0](https://img.shields.io/badge/Version-0.3.0-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 3.9.0](https://img.shields.io/badge/AppVersion-3.9.0-informational?style=flat-square)
+![Version: 0.3.1](https://img.shields.io/badge/Version-0.3.1-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 3.9.1](https://img.shields.io/badge/AppVersion-3.9.1-informational?style=flat-square)
 
 A Helm chart for a RabbitMQ cluster on Kubernetes
 
@@ -11,6 +11,14 @@ $ helm repo add groundhog2k https://groundhog2k.github.io/helm-charts/
 $ helm install my-release groundhog2k/rabbitmq
 ```
 
+# ⚠️ Attention
+
+Docker image of RabbitMQ 3.8.17 was the last one that supports multi-architecture. If you need that, please use RabbitMQ 3.8.17, which is chart version **0.2.19**.
+
+In the future RabbitMQ will support multi-architecture again. See https://github.com/docker-library/rabbitmq/issues/507 and related issue https://github.com/erlang/otp/pull/4869.
+
+#
+
 ## Introduction
 
 This chart uses the original [RabbitMQ image from Docker Hub](https://hub.docker.com/_/rabbitmq) to deploy a stateful RabbitMQ cluster in Kubernetes.