Update New-AzSentinelAlertRule.md (Azure#22114)

Typo error -Creates alert rule, not Creates or updates the alert rule.

Author: PoonamYadavMS

src/SecurityInsights/help/New-AzSentinelAlertRule.md

@@ -8,7 +8,7 @@ schema: 2.0.0
 # New-AzSentinelAlertRule
 
 ## SYNOPSIS
-Creates or updates the alert rule.
+Creates alert rule.
 
 ## SYNTAX