Add alert model

db/migrate/20251008063847_create_alerts.rb

@@ -0,0 +1,17 @@
+class CreateAlerts < ActiveRecord::Migration[8.0]
+  def change
+    create_table :alerts do |t|
+      t.string :category, null: false
+      t.text :description
+      t.string :park_code, null: false
+      t.string :title, null: false
+      t.string :url
+      t.timestamp :indexed_date
+
+      t.timestamps
+    end
+
+    add_index :alerts, :park_code
+    add_foreign_key :alerts, :parks, column: :park_code, primary_key: :code
+  end
+end