Add redirect for use in the policies UI (#17641)

Currently the policies UI links directly to the docs, but going forward
we're adding redirects for pages linked to from the Fleet UI, to make it
easier to keep those links up-to-date.

Since we're making changes to the policies UI right now, updating this
one.

website/config/routes.js

@@ -516,6 +516,7 @@ module.exports.routes = {
   'GET /learn-more-about/custom-os-settings': '/docs/using-fleet/mdm-custom-os-settings',
   'GET /learn-more-about/enrolling-hosts': '/docs/using-fleet/adding-hosts',
   'GET /learn-more-about/setup-assistant': '/docs/using-fleet/mdm-macos-setup-experience#macos-setup-assistant',
+  'GET /learn-more-about/policy-automations': '/docs/using-fleet/automations',
 
   // Sitemap
   // =============================================================================================================