Add Citadel Missing Information

README.md

@@ -208,7 +208,7 @@ _simple deployment of a mail server, e.g. for inexperienced or impatient admins.
   * [Mailcow](https://mailcow.email/) - Mail server suite based on Dovecot, Postfix and other open source software, that provides a modern Web UI for administration. ([Source Code](https://github.com/andryyy/mailcow)) `GPLv2` `PHP/Shell`
   * [Mail-in-a-Box](https://mailinabox.email/) - Turns any Ubuntu server into a fully functional mail server with one command. `CC0` `Shell/Other`
   * [iRedMail](http://www.iredmail.org/) - Full-featured mail server solution based on Postfix and Dovecot. ([Source Code](https://bitbucket.org/zhb/iredmail/commits/)) `GPLv3` `Shell`
-  * [Citadel](http://www.citadel.org/) - Feature packed, easy, versatile, and powerful mail server, thanks to exclusive "rooms" based architecture. ([Source Code](http://code.citadel.org/?p=citadel.git;a=summary))
+  * [Citadel](http://www.citadel.org/) - Feature packed, easy, versatile, and powerful mail server, thanks to exclusive "rooms" based architecture. ([Source Code](http://code.citadel.org/?p=citadel.git;a=summary)) `GNU GPL` `C`
   * [Modoboa](http://modoboa.org/en/) - Modoboa is a mail hosting and management platform including a modern and simplified Web User Interface. ([Source Code](https://github.com/tonioo/modoboa)) `MIT` `Python`