Add link to presentation (#465)

Author: wing328

README.md

@@ -416,12 +416,13 @@ Here are some companies/projects (alphabetical order) using OpenAPI Generator in
 
 ## [5 - Presentations/Videos/Tutorials/Books](#table-of-contents)
 
+- 2018/04/12 - [Generate Angular API clients with Swagger](https://angular.schule/blog/2018-04-swagger-codegen) by [JohannesHoppe](https://github.com/JohannesHoppe)
 - 2018/05/12 - [OpenAPI Generator - community drivenで成長するコードジェネレータ](https://ackintosh.github.io/blog/2018/05/12/openapi-generator/) by [中野暁人](https://github.com/ackintosh)
 - 2018/05/15 - [Starting a new open-source project](http://jmini.github.io/blog/2018/2018-05-15_new-open-source-project.html) by [Jeremie Bresson](https://github.com/jmini)
 - 2018/05/15 - [REST API仕様からAPIクライアントやスタブサーバを自動生成する「OpenAPI Generator」オープンソースで公開。Swagger Codegenからのフォーク](https://www.publickey1.jp/blog/18/rest_apiapiopenapi_generatorswagger_generator.html) by [Publickey](https://www.publickey1.jp)
-- 2018/04/12 - [Generate Angular API clients with Swagger](https://angular.schule/blog/2018-04-swagger-codegen) by [JohannesHoppe](https://github.com/JohannesHoppe)
 - 2018/06/08 - [Swagger Codegen is now OpenAPI Generator](https://angular.schule/blog/2018-06-swagger-codegen-is-now-openapi-generator) by [JohannesHoppe](https://github.com/JohannesHoppe)
 - 2018/06/21 - [Connect your JHipster apps to the world of APIs with OpenAPI and gRPC](https://fr.slideshare.net/chbornet/jhipster-conf-2018-connect-your-jhipster-apps-to-the-world-of-apis-with-openapi-and-grpc) by [Christophe Bornet](https://github.com/cbornet) at [JHipster Conf 2018](https://jhipster-conf.github.io/)
+- 2018/06/27 - [Lessons Learned from Leading an Open-Source Project Supporting 30+ Programming Languages](https://speakerdeck.com/wing328/lessons-learned-from-leading-an-open-source-project-supporting-30-plus-programming-languages) - [William Cheng](https://github.com/wing328) at [LinuxCon + ContainerCon + CloudOpen China 2018](https://www.lfasiallc.com/events/lc3-2018/)
 
 ## [6 - About Us](#table-of-contents)