fix: initial review finding fixes

Signed-off-by: Heikki Hellgren <heikki.hellgren@op.fi>

plugins/signals-node/src/index.ts

@@ -14,5 +14,6 @@
  * limitations under the License.
  */
 
+export * from './lib';
 export * from './SignalService';
 export * from './types';

plugins/signals-node/src/lib.ts

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2023 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { createServiceRef } from '@backstage/backend-plugin-api';
+
+/** @public */
+export const signalService = createServiceRef<
+  import('./SignalService').SignalService
+>({ id: 'signals.service', scope: 'plugin' });