refactor: repository pattern: rename Save() to Create()

pkg/training/feedback_repository.go

@@ -3,7 +3,7 @@ package training
 type FeedbackRepository interface {
 	Get(FeedbackID) (*Feedback, error)
 	FindAll() ([]Feedback, error)
-	Save(*Feedback) error
+	Create(*Feedback) error
 	Update(*Feedback) error
 	Delete(FeedbackID) error
 }