Use dynamic import in pipe to parse markdown

pipe-dynamic-import.ts

@Pipe({ name: 'markdownToHtml' })
export class MarkdownToHtmlPipe implements PipeTransform {
    transform(markdown: string): Observable<string> {
        return markdown 
          // import(...) will only run once per instance
          // The `marked` library will only be imported if the template
          // has markdown; <div class="markdown-container" [innerHTML]="markdownContent | markdownToHtml | async | sanitize: 'html'"></div>
          ? from(import(/* webpackPrefetch: true */ 'marked')).pipe(map(({ parse }) => parse(markdown)))
          : of('')
    }
}