chore: moved articles into the specific folder

knowledge base/kubernetes/kubeval.md

@@ -0,0 +1,19 @@
+# Kubeval
+
+Validates one or more Kubernetes configuration files.
+
+## TL;DR
+
+```sh
+$ kubeval my-invalid-rc.yaml || echo "Validation failed" >&2
+WARN - my-invalid-rc.yaml contains an invalid ReplicationController - spec.replicas: Invalid type. Expected: integer, given: string
+Validation failed
+```
+
+## Further readings
+
+- [Kubeval]
+- [Validating kubernetes YAML files with kubeval]
+
+[kubeval]: https://www.kubeval.com
+[validating kubernetes yaml files with kubeval]: https://learnk8s.io/validating-kubernetes-yaml#kubeval