Add a link to vadosware.io (OpenAPITools#5276)

Author: wing328

README.md

@@ -664,6 +664,7 @@ Here are some companies/projects (alphabetical order) using OpenAPI Generator in
 - 2019/02/26 - [Building API Services: A Beginner’s Guide](https://medium.com/google-cloud/building-api-services-a-beginners-guide-7274ae4c547f) by [Ratros Y.](https://medium.com/@ratrosy) in [Google Cloud Platofrm Blog](https://medium.com/google-cloud)
 - 2019/02/26 - [Building APIs with OpenAPI: Continued](https://medium.com/@ratrosy/building-apis-with-openapi-continued-5d0faaed32eb) by [Ratros Y.](https://medium.com/@ratrosy) in [Google Cloud Platofrm Blog](https://medium.com/google-cloud)
 - 2019-03-07 - [OpenAPI Generator で Spring Boot と Angular をタイプセーフに繋ぐ](https://qiita.com/chibato/items/e4a748db12409b40c02f) by [Tomofumi Chiba](https://github.com/chibat)
+- 2019-03-16 - [A Quick introduction to manual OpenAPI V3](https://vadosware.io/post/quick-intro-to-manual-openapi-v3/) by [vados](https://github.com/t3hmrman) at [VADOSWARE](https://vadosware.io)
 - 2019-03-25 - [Access any REST service with the SAP S/4HANA Cloud SDK](https://blogs.sap.com/2019/03/25/integrate-sap-s4hana-cloud-sdk-with-open-api/) by [Alexander Duemont](https://people.sap.com/alexander.duemont)
 - 2019-03-25 - [OpenAPI generatorを試してみる](https://qiita.com/amuyikam/items/e8a45daae59c68be0fc8) by [@amuyikam](https://twitter.com/amuyikam)
 - 2019-03-27 - [OpenAPI3を使ってみよう！Go言語でクライアントとスタブの自動生成まで！](https://techblog.zozo.com/entry/openapi3/go) by [@gold_kou](https://twitter.com/gold_kou)