Update Set-CalendarProcessing.md

Typo fix per Issue #2116

Author: chrisda

exchange/exchange-ps/exchange/mailboxes/Set-CalendarProcessing.md

@@ -150,7 +150,7 @@ Accept wildcard characters: False
 ```
 
 ### -AdditionalResponse
-The AdditionalResponse parameter specifies the additional information to be included in responses to meeting requests. This parameter is meaningful only when the AddAdditionalRepsponse parameter is set to $true.
+The AdditionalResponse parameter specifies the additional information to be included in responses to meeting requests. This parameter is meaningful only when the AddAdditionalResponse parameter is set to $true.
 
 ```yaml
 Type: String