Get list of competition

{
    "contests": [
        {
            "contest_id": 1,
            "title": "第一次练习",
            "subtitle": "22计算机3班",
            "difficulty": "简单",
            "password": "123456",
            "have_password": true,
            "is_visible": true,
            "start_at": "2024-08-19T00:00:00+08:00",
            "end_at": "2024-09-19T00:00:00+08:00"
        },
        {
            "contest_id": 2,
            "title": "测试",
            "subtitle": "临时97",
            "difficulty": "简单",
            "password": "",
            "have_password": false,
            "is_visible": true,
            "start_at": "2024-09-20T00:00:00+08:00",
            "end_at": "2024-10-20T00:00:00+08:00"
        },
        {
            "contest_id": 3,
            "title": "测",
            "subtitle": "92",
            "difficulty": "困难",
            "password": "123",
            "have_password": true,
            "is_visible": true,
            "start_at": "2024-08-19T00:00:00+08:00",
            "end_at": "2024-08-20T00:00:00+08:00"
        },
        {
            "contest_id": 4,
            "title": "测2",
            "subtitle": "123",
            "difficulty": "中等",
            "password": "",
            "have_password": false,
            "is_visible": true,
            "start_at": "2024-11-11T00:00:00+08:00",
            "end_at": "2024-12-11T00:00:00+08:00"
        },
        {
            "contest_id": 5,
            "title": "第二次Java练习",
            "subtitle": "22级人工智能2班",
            "difficulty": "困难",
            "password": "245",
            "have_password": true,
            "is_visible": true,
            "start_at": "2024-09-23T00:00:00+08:00",
            "end_at": "2024-09-24T00:00:00+08:00"
        }
    ]
}