add help for cel metrics

Signed-off-by: qingwave <isguory@gmail.com>

staging/src/k8s.io/apiserver/pkg/cel/metrics/metrics.go

@@ -43,12 +43,14 @@ func newCelMetrics() *CelMetrics {
 			Namespace:      namespace,
 			Subsystem:      subsystem,
 			Name:           "compilation_duration_seconds",
+			Help:           "CEL compilation time in seconds.",
 			StabilityLevel: metrics.ALPHA,
 		}),
 		evaluationTime: metrics.NewHistogram(&metrics.HistogramOpts{
 			Namespace:      namespace,
 			Subsystem:      subsystem,
 			Name:           "evaluation_duration_seconds",
+			Help:           "CEL evaluation time in seconds.",
 			StabilityLevel: metrics.ALPHA,
 		}),
 	}