Add Rocket.Chat Alertmanager Webhook Receiver (#1525)

Signed-off-by: Pascal Zumkehr <spam@codez.ch>

Author: codez

content/docs/operating/integrations.md

@@ -70,6 +70,7 @@ For notification mechanisms not natively supported by the Alertmanager, the
   * [JIRAlert](https://github.com/free/jiralert)
   * [Phabricator / Maniphest](https://github.com/knyar/phalerts)
   * [prom2teams](https://github.com/idealista/prom2teams): forwards notifications to Microsoft Teams
+  * [Rocket.Chat](https://rocket.chat/docs/administrator-guides/integrations/prometheus/)
   * [ServiceNow](https://github.com/FXinnovation/alertmanager-webhook-servicenow)
   * [SMS](https://github.com/messagebird/sachet): supports [multiple providers](https://github.com/messagebird/sachet/blob/master/examples/config.yaml)
   * [SNMP traps](https://github.com/maxwo/snmp_notifier)