Make the replica transformer kind aware.

The previous implementation had a bug and poorly handled
types that should not have a `spec: replica:` field.

Documentation is updated to reflect the change in behavior,
and better highlights the cases where a patch should be
used instead of this shorthand.

pkg/transformers/config/defaultconfig/defaultconfig.go

@@ -32,6 +32,7 @@ func GetDefaultFieldSpecs() []byte {
 		[]byte(varReferenceFieldSpecs),
 		[]byte(nameReferenceFieldSpecs),
 		[]byte(imagesFieldSpecs),
+		[]byte(replicasFieldSpecs),
 	}
 	return bytes.Join(configData, []byte("\n"))
 }
@@ -47,5 +48,6 @@ func GetDefaultFieldSpecsAsMap() map[string]string {
 	result["varreference"] = varReferenceFieldSpecs
 	result["namereference"] = nameReferenceFieldSpecs
 	result["images"] = imagesFieldSpecs
+	result["replicas"] = replicasFieldSpecs
 	return result
 }