annotate models (#2697)

* add annotate to Gemfile

* rails g annotate:install

* configure annotate_models

* add schema info to models

* fix rubocop to add frozen_string_literal

app/models/preview_card.rb

@@ -1,4 +1,28 @@
 # frozen_string_literal: true
+# == Schema Information
+#
+# Table name: preview_cards
+#
+#  id                 :integer          not null, primary key
+#  status_id          :integer
+#  url                :string           default(""), not null
+#  title              :string
+#  description        :string
+#  image_file_name    :string
+#  image_content_type :string
+#  image_file_size    :integer
+#  image_updated_at   :datetime
+#  created_at         :datetime         not null
+#  updated_at         :datetime         not null
+#  type               :integer          default("link"), not null
+#  html               :text             default(""), not null
+#  author_name        :string           default(""), not null
+#  author_url         :string           default(""), not null
+#  provider_name      :string           default(""), not null
+#  provider_url       :string           default(""), not null
+#  width              :integer          default(0), not null
+#  height             :integer          default(0), not null
+#
 
 class PreviewCard < ApplicationRecord
   IMAGE_MIME_TYPES = ['image/jpeg', 'image/png', 'image/gif'].freeze