Add a link to massive art blog (#8082)

Add a link to massive art blog

Author: wing328

README.md

@@ -784,6 +784,7 @@ Here are some companies/projects (alphabetical order) using OpenAPI Generator in
 - 2020-09-25 - [Generate OpenAPI Angular Client](https://medium.com/@pguso/generate-openapi-angular-client-8c9288e8bbd4) by [Patric](https://medium.com/@pguso)
 - 2020-10-24 - [Working with Microsoft Identity - React Native Client](https://www.josephguadagno.net/2020/10/24/working-with-microsoft-identity-react-native-client) by [Joseph Guadagno](https://www.josephguadagno.net/)
 - 2020-10-31 - [[B2] OpenAPI Specification으로 타입-세이프하게 API 개발하기: 희망편 VS 절망편](https://www.youtube.com/watch?v=J4JHLESAiFk) by 최태건 at [FEConf 2020](https://2020.feconf.kr/)
+- 2020-11-05 - [Automated REST-Api Code Generation: Wie IT-Systeme miteinander sprechen](https://www.massiveart.com/blog/automated-rest-api-code-generation-wie-it-systeme-miteinander-sprechen) by Stefan Rottensteiner at [MASSIVE ART Blog](https://www.massiveart.com/blog)
 - 2020-12-01 - [OpenAPI GeneratorでGoのAPIサーバー/クライアントコードを自動生成する](https://qiita.com/saki-engineering/items/b20d8b6074c4da9664a5) by [@saki-engineering](https://qiita.com/saki-engineering)
 
 ## [6 - About Us](#table-of-contents)