Add tags filter for index.

app/controllers/faqs_controller.rb

@@ -1,6 +1,6 @@
 class FaqsController < ApplicationController
   def index
-    faqs = Qa.can_display.order_by(:order_position => "asc").filter_by_categories
+    faqs = Qa.can_display.order_by(:order_position => "asc").filter_by_tags.filter_by_categories
     locale = I18n.locale.to_s
     f = faqs.collect do |qa|
        statuses = qa.statuses_with_classname.collect do |status|