docs: edit template ref vars copy and example (#27371)

PR Close #27371

aio/content/examples/template-reference-variables/src/main.ts

@@ -0,0 +1,11 @@
+import { enableProdMode } from '@angular/core';
+import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
+
+import { AppModule } from './app/app.module';
+import { environment } from './environments/environment';
+
+if (environment.production) {
+  enableProdMode();
+}
+
+platformBrowserDynamic().bootstrapModule(AppModule);