use single base URL for working crosslinks

lib/docs/filters/react/entries_react_dev.rb

@@ -10,7 +10,7 @@ module Docs
       def get_type
         breadcrumb_nodes = css('a.tracking-wide')
         category = breadcrumb_nodes.last.content
-        is_learn_page = base_url.to_s.end_with?('learn')
+        is_learn_page = path.start_with?('learn/')
         prefix = is_learn_page ? 'Learn: ' : ''
         return prefix + (category || 'Miscellaneous')
       end

lib/docs/scrapers/react.rb

@@ -1,6 +1,5 @@
 module Docs
   class React < UrlScraper
-    include MultipleBaseUrls
 
     self.name = 'React'
     self.type = 'simple'
@@ -11,15 +10,13 @@ module Docs
 
     version do
       self.release = '18.3.1'
-      host = 'https://react.dev'
-      self.base_urls = [
-        "#{host}/reference",
-        "#{host}/learn",
-      ]
-      self.initial_paths = %w(/react)
+      self.base_url = 'https://react.dev'
+      self.initial_paths = %w(/reference/react /learn)
 
       html_filters.push 'react/entries_react_dev', 'react/clean_html_react_dev'
 
+      options[:only_patterns] = [/\A\/learn/, /\A\/reference/]
+
       options[:attribution] = <<-HTML
         &copy; 2013&ndash;present Facebook Inc.<br>
         Licensed under the Creative Commons Attribution 4.0 International Public License.