chore: nxignore .opensource dir and preserve richtext newlines

- Add .nxignore to exclude vendored .opensource/ clone from Nx project
  graph (was causing duplicate-project errors vs forgerock-verdaccio).
- Render authored line breaks in ReadOnlyCollector rich text via
  white-space: pre-line on the rendered <p>.

Author: ryanbas21

.nxignore

@@ -0,0 +1 @@
+.opensource/

e2e/davinci-app/components/label.ts

@@ -8,6 +8,7 @@ import type { ReadOnlyCollector } from '@forgerock/davinci-client/types';
 
 export default function (formEl: HTMLFormElement, collector: ReadOnlyCollector) {
   const p = document.createElement('p');
+  p.style.whiteSpace = 'pre-line';
   const { richContent } = collector.output;
 
   if (richContent.replacements.length === 0) {