add ruby httpx echo api tests (#16729)

samples/client/echo_api/ruby-httpx/docs/PathApi.md

@@ -0,0 +1,74 @@
+# OpenapiClient::PathApi
+
+All URIs are relative to *http://localhost:3000*
+
+| Method | HTTP request | Description |
+| ------ | ------------ | ----------- |
+| [**tests_path_string_path_string_integer_path_integer**](PathApi.md#tests_path_string_path_string_integer_path_integer) | **GET** /path/string/{path_string}/integer/{path_integer} | Test path parameter(s) |
+
+
+## tests_path_string_path_string_integer_path_integer
+
+> String tests_path_string_path_string_integer_path_integer(path_string, path_integer)
+
+Test path parameter(s)
+
+Test path parameter(s)
+
+### Examples
+
+```ruby
+require 'time'
+require 'openapi_client'
+
+api_instance = OpenapiClient::PathApi.new
+path_string = 'path_string_example' # String | 
+path_integer = 56 # Integer | 
+
+begin
+  # Test path parameter(s)
+  result = api_instance.tests_path_string_path_string_integer_path_integer(path_string, path_integer)
+  p result
+rescue OpenapiClient::ApiError => e
+  puts "Error when calling PathApi->tests_path_string_path_string_integer_path_integer: #{e}"
+end
+```
+
+#### Using the tests_path_string_path_string_integer_path_integer_with_http_info variant
+
+This returns an Array which contains the response data, status code and headers.
+
+> <Array(String, Integer, Hash)> tests_path_string_path_string_integer_path_integer_with_http_info(path_string, path_integer)
+
+```ruby
+begin
+  # Test path parameter(s)
+  data, status_code, headers = api_instance.tests_path_string_path_string_integer_path_integer_with_http_info(path_string, path_integer)
+  p status_code # => 2xx
+  p headers # => { ... }
+  p data # => String
+rescue OpenapiClient::ApiError => e
+  puts "Error when calling PathApi->tests_path_string_path_string_integer_path_integer_with_http_info: #{e}"
+end
+```
+
+### Parameters
+
+| Name | Type | Description | Notes |
+| ---- | ---- | ----------- | ----- |
+| **path_string** | **String** |  |  |
+| **path_integer** | **Integer** |  |  |
+
+### Return type
+
+**String**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: text/plain
+