Add gitter link (#21)

Add gitter link

Signed-off-by: Keith Chong [email protected]

Author: keithchong

README.md

@@ -2,6 +2,7 @@
 
 [![License](https://img.shields.io/badge/License-EPL%202.0-red.svg?label=license&logo=eclipse)](https://www.eclipse.org/legal/epl-2.0/)
 [![Chat](https://img.shields.io/static/v1.svg?label=chat&message=mattermost&color=145dbf)](https://mattermost.eclipse.org/eclipse/channels/eclipse-codewind)
+[![Gitter](https://badges.gitter.im/OpenAPITools/openapi-generator.svg)](https://gitter.im/OpenAPITools/openapi-generator)
 
 The Codewind OpenAPI Tools for Eclipse includes wizards that invoke the OpenAPI Generator to create API clients, server stubs, and HTML documentation from OpenAPI Specifications. The tools are integrated and customized to work with Codewind for Eclipse, but they also work with a base Eclipse IDE for Java EE Developers installation.