A POST request to api/list with a timestamp attribute of latest article
would be replied with a JSON consisting of the following
| Key | Explanation | |
|---|---|---|
| 1. | r_timestamp |
the timestamp of the recieved request |
| 2. | u_timestamp |
the updated timestamp, i.e, the timestamp of the latest article being sent |
| 3. | num |
the total number of entries being sent |