Add exercise feedback page for pair programming study

db/migrate/20230905190519_add_pair_programming_exercise_feedbacks.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class AddPairProgrammingExerciseFeedbacks < ActiveRecord::Migration[7.0]
+  def change
+    create_table :pair_programming_exercise_feedbacks do |t|
+      t.references :exercise, null: false, index: true, foreign_key: true
+      t.references :submission, null: false, index: true, foreign_key: true
+      t.references :user, polymorphic: true, null: false, index: true
+      t.references :programming_group, null: true, index: {name: 'pp_feedback_programming_group'}, foreign_key: true
+      t.references :study_group, null: false, index: true, foreign_key: true
+      t.integer :difficulty
+      t.integer :user_estimated_worktime
+      t.integer :reason_work_alone
+      t.float :normalized_score
+
+      t.timestamps
+    end
+  end
+end