`RouteSet` should not be listed in the public API [ci skip]

The use of `# :startdoc:` inside of the class was overriding the
outer-most `# :nodoc:`, causing it to be listed in the documented API.

actionpack/lib/action_dispatch/routing/route_set.rb

@@ -12,14 +12,15 @@ require 'action_dispatch/routing/endpoint'
 
 module ActionDispatch
   module Routing
-    class RouteSet #:nodoc:
+    # :stopdoc:
+    class RouteSet
       # Since the router holds references to many parts of the system
       # like engines, controllers and the application itself, inspecting
       # the route set can actually be really slow, therefore we default
       # alias inspect to to_s.
       alias inspect to_s
 
-      class Dispatcher < Routing::Endpoint #:nodoc:
+      class Dispatcher < Routing::Endpoint
         def initialize(defaults)
           @defaults = defaults
           @controller_class_names = ThreadSafe::Cache.new
@@ -84,7 +85,7 @@ module ActionDispatch
       # A NamedRouteCollection instance is a collection of named routes, and also
       # maintains an anonymous module that can be used to install helpers for the
       # named routes.
-      class NamedRouteCollection #:nodoc:
+      class NamedRouteCollection
         include Enumerable
         attr_reader :routes, :url_helpers_module, :path_helpers_module
 
@@ -161,7 +162,7 @@ module ActionDispatch
           routes.length
         end
 
-        class UrlHelper # :nodoc:
+        class UrlHelper
           def self.create(route, options, route_name, url_strategy)
             if optimize_helper?(route)
               OptimizedUrlHelper.new(route, options, route_name, url_strategy)
@@ -176,7 +177,7 @@ module ActionDispatch
 
           attr_reader :url_strategy, :route_name
 
-          class OptimizedUrlHelper < UrlHelper # :nodoc:
+          class OptimizedUrlHelper < UrlHelper
             attr_reader :arg_size
 
             def initialize(route, options, route_name, url_strategy)
@@ -300,11 +301,9 @@ module ActionDispatch
         end
       end
 
-      # :stopdoc:
       # strategy for building urls to send to the client
       PATH    = ->(options) { ActionDispatch::Http::URL.path_for(options) }
       UNKNOWN = ->(options) { ActionDispatch::Http::URL.url_for(options) }
-      # :startdoc:
 
       attr_accessor :formatter, :set, :named_routes, :default_scope, :router
       attr_accessor :disable_clear_and_finalize, :resources_path_names
@@ -379,7 +378,7 @@ module ActionDispatch
         Routing::RouteSet::Dispatcher.new(defaults)
       end
 
-      module MountedHelpers #:nodoc:
+      module MountedHelpers
         extend ActiveSupport::Concern
         include UrlFor
       end
@@ -551,7 +550,7 @@ module ActionDispatch
       end
       private :build_conditions
 
-      class Generator #:nodoc:
+      class Generator
         PARAMETERIZE = lambda do |name, value|
           if name == :controller
             value
@@ -703,7 +702,7 @@ module ActionDispatch
         options.delete(:script_name) || ''
       end
 
-      def path_for(options, route_name = nil) # :nodoc:
+      def path_for(options, route_name = nil)
         url_for(options, route_name, PATH)
       end
 
@@ -789,5 +788,6 @@ module ActionDispatch
         raise ActionController::RoutingError, "No route matches #{path.inspect}"
       end
     end
+    # :startdoc:
   end
 end