Add Erxes to README under Ticketing

Closes #2191

README.md

@@ -1480,6 +1480,7 @@ See https://staticsitegenerators.net and https://www.staticgen.com
 - [Cerb](http://www.cerberusweb.com/) - Group-based e-mail management project. ([Source Code](https://github.com/wgm/cerb)) `DPL` `PHP`
 - [DiamanteDesk](http://diamantedesk.com/) - DiamanteDesk is FREE Open Source easy-to-use help-desk solution. ([Demo](http://diamantedesk.com/demo/), [Source Code](https://github.com/eltrino/diamantedesk-application)) `OSL-3.0` `PHP`
 - [django-todo](http://django-todo.org/) - django-todo is a pluggable, multi-user, multi-group, multi-list todo and ticketing system - a reusable app designed to be dropped into any existing Django project. ([Source Code](https://github.com/shacker/django-todo)) `BSD-3-Clause` `Python/Django`
+- [Erxes](https://erxes.io/) - marketing, sales, and customer service platform designed to help businesses attract more engaged customers ([Demo](https://demo.erxes.io/), [Source Code](https://github.com/erxes/erxes>)) `GPL-3.0` `Javascript`
 - [Flyspray](http://www.flyspray.org/) - Uncomplicated, web-based bug tracking system. ([Source Code](https://github.com/Flyspray/flyspray)) `GPL-2.0` `PHP`
 - [FreeScout](https://github.com/freescout-helpdesk/freescout) - Open source clone of Help Scout: email-based customer support application, help desk and shared mailbox. `AGPL-3.0` `PHP`
 - [Helpy](https://helpy.io) - Helpy is a modern, open source helpdesk customer support application. Features include knowledgebase, community discussions and support tickets integrated with email. ([Demo](https://demo.helpy.io), [Source Code](https://github.com/helpyio/helpy)) `MIT` `Ruby`