created user model

db/migrate/20240807144034_create_users.rb

@@ -1,6 +1,9 @@
 class CreateUsers < ActiveRecord::Migration[7.1]
   def change
     create_table :users do |t|
+      t.string :username
+      t.string :email
+      t.string :password_digest
 
       t.timestamps
     end

db/migrate/20240807145348_add_user_reference_to_articles.rb

@@ -0,0 +1,5 @@
+class AddUserReferenceToArticles < ActiveRecord::Migration[7.1]
+  def change
+    add_reference :articles, :user, foreign_key: true
+  end
+end