update plugins doc (#1305)

plugins/wasm-go/extensions/request-validation/README_EN.md

@@ -0,0 +1,149 @@
+---
+title: Request Protocol Validation
+keywords: [higress,request validation]
+description: Configuration reference for request protocol validation plugin
+---
+## Function Description
+The `request-validation` plugin is used to validate requests forwarded to upstream services in advance. This plugin utilizes the `JSON Schema` mechanism for data validation, capable of validating both the body and header data of requests.
+
+## Execution Attributes
+Plugin Execution Phase: `Authentication Phase`  
+Plugin Execution Priority: `220`
+
+## Configuration Fields
+| Name            | Data Type | Requirements | Default Value | Description                                       |
+|-----------------|-----------|--------------|---------------|---------------------------------------------------|
+| header_schema    | object    | Optional     | -             | Configuration for JSON Schema to validate request headers |
+| body_schema      | object    | Optional     | -             | Configuration for JSON Schema to validate request body   |
+| rejected_code    | number    | Optional     | 403           | HTTP status code returned when the request is rejected   |
+| rejected_msg     | string    | Optional     | -             | HTTP response body returned when the request is rejected  |
+| enable_swagger   | bool      | Optional     | false         | Configuration to enable Swagger documentation validation   |
+| enable_oas3      | bool      | Optional     | false         | Configuration to enable OAS3 documentation validation      |
+
+**Validation rules for header and body are the same, below is an example using body.**
+
+## Configuration Examples
+### Enumeration (Enum) Validation
+```yaml
+body_schema:
+  type: object
+  required:
+    - enum_payload
+  properties:
+    enum_payload:
+      type: string
+      enum:
+        - "enum_string_1"
+        - "enum_string_2"
+      default: "enum_string_1"
+```
+
+### Boolean Validation
+```yaml
+body_schema:
+  type: object
+  required:
+    - boolean_payload
+  properties:
+    boolean_payload:
+      type: boolean
+      default: true
+```
+
+### Number Range (Number or Integer) Validation
+```yaml
+body_schema:
+  type: object
+  required:
+    - integer_payload
+  properties:
+    integer_payload:
+      type: integer
+      minimum: 1
+      maximum: 10
+```
+
+### String Length Validation
+```yaml
+body_schema:
+  type: object
+  required:
+    - string_payload
+  properties:
+    string_payload:
+      type: string
+      minLength: 1
+      maxLength: 10
+```
+
+### Regular Expression (Regex) Validation
+```yaml
+body_schema:
+  type: object
+  required:
+    - regex_payload
+  properties:
+    regex_payload:
+      type: string
+      minLength: 1
+      maxLength: 10
+      pattern: "^[a-zA-Z0-9_]+$"
+```
+
+### Array Validation
+```yaml
+body_schema:
+  type: object
+  required:
+    - array_payload
+  properties:
+    array_payload:
+      type: array
+      minItems: 1
+      items:
+        type: integer
+        minimum: 1
+        maximum: 10
+      uniqueItems: true
+      default: [1, 2, 3]
+```
+
+### Combined Validation
+```yaml
+body_schema:
+  type: object
+  required:
+    - boolean_payload
+    - array_payload
+    - regex_payload
+  properties:
+    boolean_payload:
+      type: boolean
+    array_payload:
+      type: array
+      minItems: 1
+      items:
+          type: integer
+          minimum: 1
+          maximum: 10
+      uniqueItems: true
+      default: [1, 2, 3]
+    regex_payload:
+      type: string
+      minLength: 1
+      maxLength: 10
+      pattern: "^[a-zA-Z0-9_]+$"
+```
+
+### Custom Rejection Message
+```yaml
+body_schema:
+  type: object
+  required:
+    - boolean_payload
+  properties:
+    boolean_payload:
+      type: boolean
+rejected_code: 403
+rejected_msg: "Request rejected"
+```