nws: refactored the NWS source files to relocate normalization logic to internal/normalizers.

internal/normalizers/nws/register.go

@@ -1,3 +1,4 @@
+// FILE: ./internal/normalizers/nws/register.go
 package nws
 
 import (
@@ -5,17 +6,11 @@ import (
 )
 
 // Register registers NWS normalizers into the provided registry.
-//
-// This is intentionally empty as a stub. As normalizers are implemented,
-// register them here, e.g.:
-//
-//	reg.Register(ObservationNormalizer{})
-//	reg.Register(ForecastNormalizer{})
-//	reg.Register(AlertsNormalizer{})
 func Register(reg *fknormalize.Registry) {
 	if reg == nil {
 		return
 	}
 
-	// TODO: register NWS normalizers here.
+	// Observations
+	reg.Register(ObservationNormalizer{})
 }