Mturk create-qualification-type [--test <value>] format

Confirm by changing [ ] to [x] below:
- [x] I've gone though the [User Guide](https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-welcome.html) and the [API reference](https://docs.aws.amazon.com/cli/latest/reference/)
- [x] I've searched for [previous similar issues](https://github.com/aws/aws-cli/issues) and didn't find any solution

Issue is about usage on:
- [ ] Service API : I want to do X using Y service, what should I do?
- [x] CLI : passing arguments or cli configurations.
- [ ] Other/Not sure.

**Platform/OS/Hardware/Device**
What are you running the cli on?
- macOS Catalina 10.15.5
- aws-cli/2.0.16 Python/3.7.3 Linux/4.19.76-linuxkit botocore/2.0.0dev20

**Describe the question**

Using the requester sandbox `--endpoint-url https://mturk-requester-sandbox.us-east-1.amazonaws.com` I would like to create a qualification type with a test and answer key.

According to the documentation I can use 2 optional options `[--test ] and [--answer-key ]` (while not forgetting `--test-duration-in-seconds `).

https://awscli.amazonaws.com/v2/documentation/api/latest/reference/mturk/create-qualification-type.html

Using Qualification test and answer key require particular structures defined here:

https://docs.aws.amazon.com/AWSMechTurk/latest/AWSMturkAPI/ApiReference_QuestionFormDataStructureArticle.html

https://docs.aws.amazon.com/AWSMechTurk/latest/AWSMturkAPI/ApiReference_AnswerKeyDataStructureArticle.html

Is it possible to have an example how do you pass the content to the `aws mturk create-qualification-type ...` options:
- `--test `
- `--answer-key `

Thxs

从 AWS CLI 的 create-qualification-type 参考文档以及链接的 QuestionFormData 和 AnswerKeyData 结构文档开始。验证 --test 和 --answer-key 的值是如何传递的，然后记录能够与 requester sandbox 端点配合工作的完整命令示例，并包含必需的测试时长。

由索引模型根据 Issue 内容生成。