Merge pull request #673 from planetscale/release-notes-2.15.0

Release notes for `v2.15.0`

Author: frouioui

docs/release-notes/2_15_0_summary.md

@@ -1,12 +1,53 @@
 ## Major Changes
 
-### etcd Upgrade Path
+### Table of Contents
+
+- **[Kubernetes Version](#k8s-version)**
+- **[Golang Version](#go-version)**
+- **[Scheduled Backups now use VTBackup](#vtbackup-scheduled-backups)**
+- **[Multiple Namespaces in the Default Examples](#multiple-namespaces)**
+- **[Upgrade Path](#upgrade-path)**
+  - **[etcd](#etcd-upgrade-path)**
+  - **[MySQL](#mysql-upgrade-path)**
+
+### <a id="k8s-version"/>Kubernetes Version</a>
+
+The default supported version of Kubernetes was bumped from `v1.31` to `v1.32`. ([#670](https://github.com/planetscale/vitess-operator/pull/670))
+
+### <a id="go-version"/>Golang Version</a>
+
+The default Golang version was bumped from `v1.23` to `v1.24`. ([#664](https://github.com/planetscale/vitess-operator/pull/664))
+
+
+### <a id="vtbackup-scheduled-backups"/>Scheduled Backups now use VTBackup</a>
+
+Scheduled backups were previously introduced in `v2.13.0` by [#553](https://github.com/planetscale/vitess-operator/pull/553),
+the original design used `vtctldclient` commands to take new backups of the cluster.
+
+This design has changed in `v2.15.0`, the `VitessScheduledBackups` controller now uses `vtbackup` pods to take
+new backups. While it uses more resources, the new design is more fault-tolerant and will not take a serving tablet out of the tablet pool.
+
+This change was introduced in [#658](https://github.com/planetscale/vitess-operator/pull/658).
+
+### <a id="multiple-namespaces"/>Multiple Namespaces in the Default Examples</a>
+
+Since [#666](https://github.com/planetscale/vitess-operator/pull/666), end-users can learn how to setup a cluster on multiple namespaces
+(e.g. `vitess-operator` in the `default` namespace, and `VitessCluster` in another namespace)
+by following the [default K8S user-guide](https://vitess.io/docs/22.0/get-started/operator/).
+
+The default `operator.yaml` provided as an example has been updated to contain all the configuration required to run the examples on multiple namespaces.
+
+All end-to-end CI tests also run with two namespaces.
+
+### <a id="upgrade-path"/>Upgrade Path</a>
+
+#### <a id="etcd-upgrade-path"/>etcd</a>
 
 We have changed the default etcd version to `3.5.17`.
 
 You can upgrade by changing your YAML file to use the new Docker Image (`quay.io/coreos/etcd:v3.5.17`).
 
-### MySQL Upgrade Path
+#### <a id="mysql-upgrade-path"/>MySQL</a>
 
 With the latest version of Vitess (`v22.0.0`) the default MySQL version changed from `8.0.30` to `8.0.40`.