Add Redux and use it for state management

app/javascript/interfaces/IPost.ts

@@ -2,13 +2,10 @@ interface IPost {
   id: number;
   title: string;
   description?: string;
-  board_id: number;
-  post_status_id?: number;
-  user_id: number;
-  created_at: string;
-
-  // associations
-  postStatus?: any;
+  boardId: number;
+  postStatusId?: number;
+  userId: number;
+  createdAt: string;
 }
 
 export default IPost;