feat: add sitemap for help center (#9280)

* feat: start sitemap

* feat: add base url and last mod to sitemap

* fix: typo

* test: sitemap generation

* test: add draft articles

* fix: escape dots in regex matching

* feat: perpend protocol to the url

* feat: use ChatwootApp.help_center_root

* feat: don't parse the URL

* fix: function declaration

app/controllers/public/api/v1/portals_controller.rb

@@ -6,6 +6,12 @@ class Public::Api::V1::PortalsController < Public::Api::V1::Portals::BaseControl
 
   def show; end
 
+  def sitemap
+    @help_center_url = @portal.custom_domain || ChatwootApp.help_center_root
+    # if help_center_url does not contain a protocol, prepend it with https
+    @help_center_url = "https://#{@help_center_url}" unless @help_center_url.include?('://')
+  end
+
   private
 
   def portal