Add blog Mustache templates with OpenAPI generator (#15198)

README.md

@@ -893,6 +893,7 @@ Here are some companies/projects (alphabetical order) using OpenAPI Generator in
 - 2022-04-06 - [Effective Software Development using OpenAPI Generator](https://apexlabs.ai/post/openapi-generator) by Ajil Oommen (Senior Flutter Developer)
 - 2022-05-13 - [A Path From an API To Client Libraries](https://www.youtube.com/watch?v=XC8oVn_efTw) by [Filip Srnec](https://www.devoxx.co.uk/talk/?id=11211) at Infobip
 - 2022-06-01 - [API First, using OpenAPI and Spring Boot](https://medium.com/xgeeks/api-first-using-openapi-and-spring-boot-2602c04bb0d3) by [Micael Estrázulas Vianna](https://estrazulas.medium.com/)
+- 2022-06-12 - [Mustache templates with OpenAPI specs](https://medium.com/geekculture/mustache-templates-with-openapi-specs-f24711c67dec) by [Beppe Catanese](https://github.com/gcatanese)
 - 2022-07-01 - [Generate API contract using OpenAPI Generator Maven plugin](https://huongdanjava.com/generate-api-contract-using-openapi-generator-maven-plugin.html) by [Khanh Nguyen](https://huongdanjava.com/)
 - 2022-07-22 - [使用OpenAPI Generator Maven plugin开发api优先的java客户端和服务端代码](https://blog.roccoshi.top/2022/java/openapi-generator%E7%9A%84%E4%BD%BF%E7%94%A8/) by [Lincest](https://github.com/Lincest)
 - 2022-08-01 - [Tutorial: Etsy Open API v3 (ruby)](https://blog.tjoyal.dev/etsy-open-api-v3/) by [Thierry Joyal](https://github.com/tjoyal)