add best practices badge (#927)

Signed-off-by: Daniel Holbach <daniel.holbach@gmail.com>

README.md

@@ -3,6 +3,7 @@
 [![Artifact HUB](https://img.shields.io/endpoint?url=https://artifacthub.io/badge/repository/kured)](https://artifacthub.io/packages/helm/kured/kured)
 [![FOSSA Status](https://app.fossa.com/api/projects/git%2Bgit.luolix.top%2Fkubereboot%2Fkured.svg?type=shield)](https://app.fossa.com/projects/git%2Bgit.luolix.top%2Fkubereboot%2Fkured?ref=badge_shield)
 [![CLOMonitor](https://img.shields.io/endpoint?url=https://clomonitor.io/api/projects/cncf/kured/badge)](https://clomonitor.io/projects/cncf/kured)
+[![OpenSSF Best Practices](https://www.bestpractices.dev/projects/8867/badge)](https://www.bestpractices.dev/projects/8867)
 
 <img src="https://github.com/kubereboot/website/raw/main/static/img/kured.png" alt="kured logo" width="200" align="right"/>