docs: Add the type parameter to the create_alert docs (#168)

Author: tembleking

sdcclient/_monitor.py

@@ -102,6 +102,7 @@ def create_alert(self, name=None, description=None, severity=None, for_atleast_s
             - **enabled**: if True, the alert will be enabled when created.
             - **annotations**: an optional dictionary of custom properties that you can associate to this alert for automation or management reasons
             - **alert_obj**: an optional fully-formed Alert object of the format returned in an "alerts" list by :func:`~SdcClient.get_alerts` This is an alternative to creating the Alert using the individual parameters listed above.
+            - **type**: the type of the alert, "MANUAL" if the alert uses a normal query, "PROMETHEUS" if it's PromQL
 
         **Success Return Value**
             A dictionary describing the just created alert, with the format described at `this link <https://app.sysdigcloud.com/apidocs/#!/Alerts/post_api_alerts>`__