Add sample spec to catch external file reference issues in swagger-parser (#17773)

* add a sample that catches swagger-parser issues with external refs

* generate samples for new test spec

samples/client/echo_api/go-external-refs/docs/AuthAPI.md

@@ -0,0 +1,132 @@
+# \AuthAPI
+
+All URIs are relative to *http://localhost:3000*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**TestAuthHttpBasic**](AuthAPI.md#TestAuthHttpBasic) | **Post** /auth/http/basic | To test HTTP basic authentication
+[**TestAuthHttpBearer**](AuthAPI.md#TestAuthHttpBearer) | **Post** /auth/http/bearer | To test HTTP bearer authentication
+
+
+
+## TestAuthHttpBasic
+
+> string TestAuthHttpBasic(ctx).Execute()
+
+To test HTTP basic authentication
+
+
+
+### Example
+
+```go
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	openapiclient "github.com/GIT_USER_ID/GIT_REPO_ID"
+)
+
+func main() {
+
+	configuration := openapiclient.NewConfiguration()
+	apiClient := openapiclient.NewAPIClient(configuration)
+	resp, r, err := apiClient.AuthAPI.TestAuthHttpBasic(context.Background()).Execute()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error when calling `AuthAPI.TestAuthHttpBasic``: %v\n", err)
+		fmt.Fprintf(os.Stderr, "Full HTTP response: %v\n", r)
+	}
+	// response from `TestAuthHttpBasic`: string
+	fmt.Fprintf(os.Stdout, "Response from `AuthAPI.TestAuthHttpBasic`: %v\n", resp)
+}
+```
+
+### Path Parameters
+
+This endpoint does not need any parameter.
+
+### Other Parameters
+
+Other parameters are passed through a pointer to a apiTestAuthHttpBasicRequest struct via the builder pattern
+
+
+### Return type
+
+**string**
+
+### Authorization
+
+[http_auth](../README.md#http_auth)
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: text/plain
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints)
+[[Back to Model list]](../README.md#documentation-for-models)
+[[Back to README]](../README.md)
+
+
+## TestAuthHttpBearer
+
+> string TestAuthHttpBearer(ctx).Execute()
+
+To test HTTP bearer authentication
+
+
+
+### Example
+
+```go
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	openapiclient "github.com/GIT_USER_ID/GIT_REPO_ID"
+)
+
+func main() {
+
+	configuration := openapiclient.NewConfiguration()
+	apiClient := openapiclient.NewAPIClient(configuration)
+	resp, r, err := apiClient.AuthAPI.TestAuthHttpBearer(context.Background()).Execute()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error when calling `AuthAPI.TestAuthHttpBearer``: %v\n", err)
+		fmt.Fprintf(os.Stderr, "Full HTTP response: %v\n", r)
+	}
+	// response from `TestAuthHttpBearer`: string
+	fmt.Fprintf(os.Stdout, "Response from `AuthAPI.TestAuthHttpBearer`: %v\n", resp)
+}
+```
+
+### Path Parameters
+
+This endpoint does not need any parameter.
+
+### Other Parameters
+
+Other parameters are passed through a pointer to a apiTestAuthHttpBearerRequest struct via the builder pattern
+
+
+### Return type
+
+**string**
+
+### Authorization
+
+[http_bearer_auth](../README.md#http_bearer_auth)
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: text/plain
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints)
+[[Back to Model list]](../README.md#documentation-for-models)
+[[Back to README]](../README.md)
+