chore: Update Help Center APIs to accomodate locale (#4515)

app/models/kbase/category.rb

@@ -4,6 +4,7 @@
 #
 #  id          :bigint           not null, primary key
 #  description :text
+#  locale      :string           default("en")
 #  name        :string
 #  position    :integer
 #  created_at  :datetime         not null
@@ -11,6 +12,10 @@
 #  account_id  :integer          not null
 #  portal_id   :integer          not null
 #
+# Indexes
+#
+#  index_kbase_categories_on_locale_and_account_id  (locale,account_id)
+#
 class Kbase::Category < ApplicationRecord
   belongs_to :account
   belongs_to :portal