Redesign landing page (#10232)

app/controllers/public_timelines_controller.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+class PublicTimelinesController < ApplicationController
+  layout 'public'
+
+  before_action :check_enabled
+  before_action :set_body_classes
+  before_action :set_instance_presenter
+
+  def show
+    respond_to do |format|
+      format.html do
+        @initial_state_json = ActiveModelSerializers::SerializableResource.new(
+          InitialStatePresenter.new(settings: { known_fediverse: Setting.show_known_fediverse_at_about_page }, token: current_session&.token),
+          serializer: InitialStateSerializer
+        ).to_json
+      end
+    end
+  end
+
+  private
+
+  def check_enabled
+    raise ActiveRecord::RecordNotFound unless Setting.timeline_preview
+  end
+
+  def set_body_classes
+    @body_classes = 'with-modals'
+  end
+
+  def set_instance_presenter
+    @instance_presenter = InstancePresenter.new
+  end
+end