add redis upgrade notice

Author: marcosbc

bitnami/harbor/README.md

@@ -354,7 +354,10 @@ Bitnami will release a new chart updating its containers if a new version of the
 
 ## 2.0.0
 
-In this version, this **chart depends on PostgreSQL 11 instead of PostgreSQL 10**. You can find the main difference and notable changes in the following links: [https://www.postgresql.org/about/news/1894/](https://www.postgresql.org/about/news/1894/) and [https://www.postgresql.org/about/featurematrix/](https://www.postgresql.org/about/featurematrix/).
+In this version, two major changes were performed:
+
+- This **chart depends on the Redis 5 chart instead of Redis 4**. There is a breaking change that will affect releases with `metrics.enabled: true`, since the default tag for the exporter image is now `v1.x.x`. This introduces many changes including metrics names. You'll want to use [this dashboard](https://github.com/oliver006/redis_exporter/blob/master/contrib/grafana_prometheus_redis_dashboard.json) now. Please see the [redis_exporter github page](https://github.com/oliver006/redis_exporter#upgrading-from-0x-to-1x) for more details.
+- This **chart depends on the PostgreSQL 11 chart instead of PostgreSQL 10**. You can find the main difference and notable changes in the following links: [https://www.postgresql.org/about/news/1894/](https://www.postgresql.org/about/news/1894/) and [https://www.postgresql.org/about/featurematrix/](https://www.postgresql.org/about/featurematrix/).
 
 For major releases of PostgreSQL, the internal data storage format is subject to change, thus complicating upgrades, you can see some errors like the following one in the logs: