[v3] Implement new Concept Exercise: `Map`

先阅读链接的 v3 Features、Rationale、Concept-Exercise 和 Anatomy 文档，然后再检查现有的 Clojure 概念练习。为一个专注于将函数映射到集合上的 Map 练习创建列出的 .docs、.meta、练习和测试文件，其中概念为 higher-order-functions，transducers 不在范围内。当练习结构、文档、示例、实现和测试全部完成时，即视为完成。

This issue describes how to implement the Map concept exercise for the Clojure track.

Getting started

Please please please read the docs before starting. Posting PRs without reading these docs will be a lot more frustrating for you during the review cycle, and exhaust Exercism's maintainers' time. So, before diving into the implementation, please read up on the following documents:

• The features of v3.
• Rationale for v3.
• What are concept exercise and how they are structured?

Please also watch the following video:

• The Anatomy of a Concept Exercise.

Goal

The goal of this exercise is to teach the student how the map function is implemented in Clojure.

Learning objectives

The student will gain a general understanding of:

• The concept of mapping a function on a collection

Out of scope

• Transducers

Concepts

• higher-order-functions

Prerequisites

• basics

Resources to refer to

Clojure for the Brave and True - Core Functions in Depth

Representer

The Clojure Representer is currently being implemented and contributions are welcome.

Analyzer

The Clojure Analyzer is currently being implemented and contributions are welcome.

Implementing

To implement a concept exercise, the following files must be created:

languages
└── clojure
    └── exercises
        └── concept
            └── <SLUG>
                ├── .docs
                |   ├── instructions.md
                |   ├── introduction.md
                |   ├── hints.md
                |   └── after.md (optional)
                ├── .meta
                |   |── design.md
                |   └── Example.clj
                ├── <NAME>.clj
                └── <NAME>_test.clj

Help

If you have any questions while implementing the exercise, please post the questions as comments in this issue.