Add highlights

db/migrate/20240405092210_create_highlights.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+ROM::SQL.migration do
+  change do
+    create_table :highlights do
+      primary_key :id
+      foreign_key :post_id, :posts, null: false
+      column :text, :text, null: false
+
+      index :post_id
+    end
+  end
+end