Add instructions to wait for questions to appear

Assignment1.md

@@ -9,3 +9,4 @@
 | 3        | Set up the environment variables in `.env` for `backend/question-service` and `frontend`.                                                                                                                                                                                 |
 | 4        | `cd` into `backend/question-service` and `frontend`. Run `npm install` to install the dependencies for `question-service` and `frontend`. Note: You may need to run `npm i --save-dev @types/cors` and `npm i --save-dev @types/express` should you encounter any errors. |
 | 5        | In `frontend` and `backend/question-service`, run `npm start`. Access the frontend by navigating to `localhost:3000` in your browser.                                                                                                                                     |
+| 6        | The landing page will show "No questions found" at first. This is because all our questions in the database are scraped from Leetcode, so it would take a while, as long as 2 minutes, to load all 2354 questions. Wait for the questions to appear on the landing page before performing CRUD. |