Treat qmd and rmd extensions as Markdown (#33786)

GitOrigin-RevId: 89d79e958ea08f3388bde8dc561b04f87a1b6549

services/web/frontend/js/features/source-editor/languages/index.ts

@@ -55,7 +55,7 @@ export const languages = [
   }),
   LanguageDescription.of({
     name: 'markdown',
-    extensions: ['md', 'markdown'],
+    extensions: ['md', 'markdown', 'qmd', 'rmd'],
     load: () => {
       return import('./markdown').then(m => m.markdown())
     },