[kotlin][client] move info to readme (#13649)

* [kotlin][client] move info to readme

* [kotlin][client] update sample projects

samples/client/petstore/kotlin-enum-default-value/README.md

@@ -1,5 +1,14 @@
 # org.openapitools.client - Kotlin client library for Issue 10591 Enum default value
 
+No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+
+## Overview
+This API client was generated by the [OpenAPI Generator](https://openapi-generator.tech) project.  By using the [openapi-spec](https://github.com/OAI/OpenAPI-Specification) from a remote server, you can easily generate an API client.
+
+- API version: latest
+- Package version: 
+- Build package: org.openapitools.codegen.languages.KotlinClientCodegen
+
 ## Requires
 
 * Kotlin 1.4.30

samples/client/petstore/kotlin-enum-default-value/src/main/kotlin/org/openapitools/client/apis/DefaultApi.kt

@@ -1,14 +1,9 @@
 /**
- * Issue 10591 Enum default value
- *
- * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
- *
- * The version of the OpenAPI document: latest
- * 
  *
  * Please note:
  * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
  * Do not edit this file manually.
+ *
  */
 
 @file:Suppress(

samples/client/petstore/kotlin-enum-default-value/src/main/kotlin/org/openapitools/client/models/ModelWithEnumPropertyHavingDefault.kt

@@ -1,14 +1,9 @@
 /**
- * Issue 10591 Enum default value
- *
- * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
- *
- * The version of the OpenAPI document: latest
- * 
  *
  * Please note:
  * This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
  * Do not edit this file manually.
+ *
  */
 
 @file:Suppress(