Website: Update sitemap (#45751)

Changes:
- Added pages in the landing-pages folder and two article category pages
to the sitemap.

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## Summary by CodeRabbit

* **Chores**
* Added whitepapers and webinars pages, along with additional landing
pages to the sitemap for broader site coverage.

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website/api/controllers/download-sitemap.js

@@ -62,6 +62,8 @@ module.exports = {
       '/announcements',// « article category page
       '/deploy',// « article category page
       '/podcasts',// « article category page
+      '/whitepapers',// « article category page
+      '/webinars',// « article category page
       // Product category pages:
       '/orchestration',
       '/device-management',
@@ -84,6 +86,14 @@ module.exports = {
       '/customers',
       '/gitops-workshop',
       '/download',
+
+      // Landing pages:
+      '/lp/patch-faster',
+      '/lp/replace-jamf',
+      '/lp/autonomous-endpoint-management',
+      '/lp/apple-mdm',
+      '/lp/on-premise',
+      '/lp/open-source',
       // FUTURE: Do something smarter to get hand-coded HTML pages from routes.js, like how rebuild-cloud-sdk works, to avoid this manual duplication.
       // See also https://github.com/sailshq/sailsjs.com/blob/b53c6e6a90c9afdf89e5cae00b9c9dd3f391b0e7/api/helpers/get-pages-for-sitemap.js#L27
     ];