Add a link to the speaker deck at Kubernetes Contributor Summit

Add a link to the speaker deck at Kubernetes Contributor Summit

PR checklist

• Read the contribution guidelines.
• Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh, ./bin/openapi3/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\. If contributing template-only or documentation-only changes which will change sample output, be sure to build the project first.
• Filed the PR against the correct branch: master, 4.1.x, 5.0.x. Default: master.
• Copied the technical committee to review the pull request if your PR is targeting a particular programming language.

Description of the PR

(details of the change, additional tests that have been done, reference to the issue for tracking, etc)

README.md

@@ -591,7 +591,8 @@ Here are some companies/projects (alphabetical order) using OpenAPI Generator in
 - 2019-05-01 - [Design and generate a REST API from Swagger / OpenAPI in Java, Python, C# and more](https://simply-how.com/design-and-generate-api-code-from-openapi) by [Simply How](https://simply-how.com/)
 - 2019-05-17 - [Generate Spring Boot REST API using Swagger/OpenAPI](https://www.47northlabs.com/knowledge-base/generate-spring-boot-rest-api-using-swagger-openapi/) by [Antonie Zafirov](https://www.47northlabs.com/author/antonie-zafirov/)
 - 2019-05-22 - [REST APIs代码生成指南(OpenAPI Generator)](https://gum.co/openapi_generator_ebook_gb) by [William Cheng](https://twitter.com/wing328), [Xin Meng](https://github.com/xmeng1)
-- 2019-05/24 - [REST API 代碼生成指南 (OpenAPI Generator)](https://gum.co/openapi_generator_ebook_big5) by [William Cheng](https://twitter.com/wing328)
+- 2019-05-24 - [REST API 代碼生成指南 (OpenAPI Generator)](https://gum.co/openapi_generator_ebook_big5) by [William Cheng](https://twitter.com/wing328)
+- 2019-06-24 - [Kubernetes Clients and OpenAPI Generator](https://speakerdeck.com/wing328/kubernetes-clients-and-openapi-generator) by [William Cheng] at [Kubernetes Contributor Summits Shanghai 2019]
 
 ## [6 - About Us](#table-of-contents)