docs: ignore files from app compilation for ngmodule-faq example (#28592)

PR Close #28592

aio/content/examples/ngmodule-faq/src/app/highlight.directive.1.ts

@@ -0,0 +1,15 @@
+// #docplaster
+// #docregion
+import { Directive, ElementRef } from '@angular/core';
+
+// Highlight the host element in gold
+@Directive({ selector: '[highlight]' })
+export class HighlightDirective {
+  constructor(el: ElementRef) {
+    el.nativeElement.style.backgroundColor = 'gold';
+    // #enddocregion
+    console.log(`* AppRoot highlight called for ${el.nativeElement.tagName}`);
+    // #docregion
+  }
+}
+// #enddocregion