feat: PayloadDocumentationExtension 구현

api/src/test/kotlin/com/few/api/web/controller/helper/PayloadDocumentationExtension.kt

@@ -0,0 +1,29 @@
+package com.few.api.web.controller.helper
+
+import org.springframework.restdocs.payload.FieldDescriptor
+import org.springframework.restdocs.payload.JsonFieldType
+
+fun FieldDescriptor.fieldWithObject(description: String): FieldDescriptor {
+    return this.type(JsonFieldType.OBJECT).description(description)
+}
+
+fun FieldDescriptor.fieldWithArray(description: String): FieldDescriptor {
+    return this.type(JsonFieldType.ARRAY).description(description)
+}
+
+fun FieldDescriptor.fieldWithString(description: String): FieldDescriptor {
+    return this.type(JsonFieldType.STRING).description(description)
+}
+
+fun FieldDescriptor.fieldWithNumber(description: String): FieldDescriptor {
+    return this.type(JsonFieldType.NUMBER).description(description)
+}
+
+fun FieldDescriptor.fieldWithBoolean(description: String): FieldDescriptor {
+    return this.type(JsonFieldType.BOOLEAN).description(description)
+}
+
+fun FieldDescriptor.fieldWithNull(description: String): FieldDescriptor {
+    return this.type(JsonFieldType.NULL).description(description)
+}
+class PayloadDocumentationExtension