improve Enum documentation (#1312)

* improve enum doc

* add prev and next

* Add examples for enum validation in JSON schema reference

* improve doc

* add no

Author: techmannih

pages/understanding-json-schema/reference/enum.md

@@ -9,50 +9,97 @@ next:
   url: /understanding-json-schema/reference/const
 ---
 
+
 The `enum` [keyword](../../learn/glossary#keyword) is used to restrict a value to a fixed set of values.
-It must be an array with at least one element, where each element is
-unique.
+It must be an array with at least one element, where each element is unique.
+
+Below are several examples demonstrating its usage.
+
+### Basic Example: Street Light Colors
+
+This example demonstrates how to validate that the `color` property of a street light is either "red", "amber", or "green".
+
+```json
+// props { "isSchema": true }
+{
+  "properties": {
+    "color": {
+      "enum": ["red", "amber", "green"]
+    }
+  }
+}
+```
+```json
+// props { "indent": true, "valid": true }
+{  "color": "red" }
+```
+
+```json
+// props { "indent": true, "valid": false }
+{  "color": "blue" }
+```
 
-The following is an example for validating street light colors:
+### Extended Example: Accepting Multiple Data Types
+
+Enums can be used without explicitly setting a data type, allowing different types of values.
+In the following example, the schema is extended to include `null` (to represent an "off" state) and the number 42.
 
 ```json
 // props { "isSchema": true }
 {
-  "enum": ["red", "amber", "green"]
+  "properties": {
+    "color": {
+      "enum": ["red", "amber", "green", null, 42]
+    }
+  }
 }
 ```
+
 ```json
 // props { "indent": true, "valid": true }
-"red"
+{ "color": null }
 ```
+
+```json
+// props { "indent": true, "valid": true }
+{ "color": 42 }
+```
+
 ```json
 // props { "indent": true, "valid": false }
-"blue"
+{ "color": 0 }
 ```
 
-You can use `enum` even without a type, to accept values of different
-types. Let\'s extend the example to use `null` to indicate \"off\", and
-also add 42, just for fun.
+
+### Additional Example: Mixed Types for Shape
 
 ```json
 // props { "isSchema": true }
 {
-  "enum": ["red", "amber", "green", null, 42]
+  "properties": {
+    "shape": {
+      "enum": ["circle", "square", 1, null]
+    }
+  }
 }
 ```
+
 ```json
 // props { "indent": true, "valid": true }
-"red"
+{ "shape": "circle" }
 ```
+
 ```json
 // props { "indent": true, "valid": true }
-null
+{ "shape": 1 }
 ```
+
 ```json
 // props { "indent": true, "valid": true }
-42
+{ "shape": null }
 ```
+
 ```json
 // props { "indent": true, "valid": false }
-0
-```
+{ "shape": "triangle" }
+```