Update New-CsTeamsEventsPolicy.md

Added description for AllowTownhalls policy

Author: navirdee

teams/teams-ps/teams/New-CsTeamsEventsPolicy.md

@@ -47,6 +47,26 @@ Possible values are:
 
 
 
+```yaml
+Type: String
+Parameter Sets: (All)
+Aliases:
+
+Required: True
+Position: Named
+Default value: Enabled
+Accept pipeline input: False
+Accept wildcard characters: False
+```
+
+### -AllowTownhalls
+This setting governs if a user can create town halls using Teams Events. 
+Possible values are:
+ - **Enabled**: Enables creating town halls.
+ - **Disabled**: Disables creating town hall.
+
+
+
 ```yaml
 Type: String
 Parameter Sets: (All)