website/docs: create draft release notes for 2026.5 (#20529)

* create draft release notes for `2026.5`

* fixup! create draft release notes for `2026.5`

website/docs/releases/2026/v2026.5.md

@@ -0,0 +1,47 @@
+---
+title: Release 2026.5
+slug: "/releases/2026.5"
+draft: true
+---
+
+## Highlights
+
+<!-- ## Breaking changes -->
+
+## New features and improvements
+
+## Upgrading
+
+This release does not introduce any new requirements. You can follow the upgrade instructions below; for more detailed information about upgrading authentik, refer to our [Upgrade documentation](../install-config/upgrade.mdx).
+
+:::warning
+When you upgrade, be aware that the version of the authentik instance and of any outposts must be the same. We recommended that you always upgrade any outposts at the same time you upgrade your authentik instance.
+:::
+
+### Docker Compose
+
+To upgrade, download the new docker-compose file and update the Docker stack with the new version, using these commands:
+
+```shell
+wget -O docker-compose.yml https://goauthentik.io/version/2026.5/docker-compose.yml
+docker compose up -d
+```
+
+The `-O` flag retains the downloaded file's name, overwriting any existing local file with the same name.
+
+### Kubernetes
+
+Upgrade the Helm Chart to the new version, using the following commands:
+
+```shell
+helm repo update
+helm upgrade authentik authentik/authentik -f values.yaml --version ^2026.5
+```
+
+## Minor changes/fixes
+
+<!-- _Insert the output of `make gen-changelog` here_ -->
+
+## API Changes
+
+<!-- _Insert output of `make gen-diff` here_ -->