add generated header

Author: tg123

gen/KubernetesWatchGenerator/VersionConverter.cs.template

@@ -1,3 +1,8 @@
+// <auto-generated>
+// Code generated by gen/KubernetesWatchGenerator
+// Changes may cause incorrect behavior and will be lost if the code is
+// regenerated.
+// </auto-generated>
 using AutoMapper;
 using k8s.Models;