add screen reader mode

app/models/document_metadata.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: document_metadata
+#
+#  id            :bigint           not null, primary key
+#  blob_checksum :string           not null
+#  text_runs     :text             not null
+#  created_at    :datetime         not null
+#  account_id    :bigint           not null
+#
+# Indexes
+#
+#  index_document_metadata_on_account_id_and_blob_checksum  (account_id,blob_checksum) UNIQUE
+#
+# Foreign Keys
+#
+#  fk_rails_...  (account_id => accounts.id)
+#
+class DocumentMetadata < ApplicationRecord
+  belongs_to :account
+
+  attribute :text_runs, :string, default: -> { {} }
+
+  serialize :text_runs, coder: JSON
+end