Add runbook of adding a new release. (#450)

Signed-off-by: xuezhaojun <[email protected]>

RELEASE_RUNBOOK.md

@@ -0,0 +1,33 @@
+# Release Runbook
+
+This document describes the steps to create a new release for the Open Cluster Management documentation website.
+
+## Prerequisites
+
+- You must have owner permissions for this repository (ability to create new release branches)
+- You must have owner permissions for the Netlify open-cluster-management.io project
+
+## Release Steps
+
+### 1. Update Version Configuration
+
+Edit the `hugo.yaml` file to add the new version. For example, to add version v0.15:
+
+```yaml
+versions:
+  - version: main
+    url: "https://open-cluster-management.io"
+  - version: v0.15
+    url: "https://v0-15--open-cluster-management.io"
+```
+
+### 2. Create Release Branch
+
+After the version update is committed, create a new release branch from that commit.
+
+### 3. Configure Netlify Branch Deploy
+
+1. Go to the [Netlify branches-and-deploy-contexts](https://app.netlify.com/sites/open-cluster-management/configuration/deploys#branches-and-deploy-contexts) section
+2. Under "Branch deploys", add the new release branch name (e.g., `v0.15`)
+
+After completing these steps, the new version will appear in the version selector in the top right corner of the documentation website.