Plugin list added

Guides/kanboard.md

@@ -14,6 +14,28 @@ Use script `install-kanboard` in the folder `Install` in this repository.
 
 ### GitHub authentication
 
+Use the GitHub authentification plugin.
+
 ### Website domain
 
 In _Settings/Application Settings_.
+
+## Plugins
+
+### Install
+
+Go to the plugins settings (you should be logged as an admin).
+
+### Useful plugins
+
+[GitHub authentication](https://github.com/kanboard/plugin-github-auth)
+
+[Gogs webhook](https://github.com/kanboard/plugin-gogs-webhook)
+
+[Mattermost notification](https://github.com/kanboard/plugin-mattermost)
+
+[Zulip notifications](https://github.com/ptr0x01/kanboard-plugin-zulip)
+
+[Signal notification](https://github.com/stratmaster/kanboard-plugin-signal)
+
+[SMS two factor authentication](https://github.com/kanboard/plugin-sms-2fa)