新增常量和变量题目

data/1.Go语言初阶/1.快速上手/1.Go安装与配置/version.json

 {
-  "type": "code_options",
-  "author": "dengmengmian",
-  "source": "version.md",
-  "notebook_enable": false,
-  "exercise_id": "9d7860ed625c4fe1b3d60b7a84be1803"
+    "type": "code_options",
+    "author": "dengmengmian",
+    "source": "version.md",
+    "notebook_enable": false,
+    "exercise_id": "9d7860ed625c4fe1b3d60b7a84be1803"
 }
\ No newline at end of file

data/1.Go语言初阶/2.初窥门径/1.go变量和常量/const.json

+{
+    "type": "code_options",
+    "author": "dengmengmian",
+    "source": "const.md",
+    "notebook_enable": false
+}
\ No newline at end of file

data/1.Go语言初阶/2.初窥门径/1.go变量和常量/const.md

+# 变量
+以下常量声明不正确的是：
+
+## 答案
+
+`var b string = "abc"`
+
+## 选项
+
+### A
+
+```go
+
+const b string = "abc"
+
+```
+### B
+
+```go
+
+const PI = 3.14159
+
+```
+
+### C
+
+```go
+const (
+        name = "gotribe.cn"
+        age = 1
+        country = "bejing"
+    )
+```