fixes accounting tag, should be uppercase

Author: RettBehrens

xero_accounting.yaml

@@ -1069,7 +1069,7 @@ paths:
       security:
         - OAuth2: [accounting.transactions, accounting.transactions.read]
       tags:
-        - accounting
+        - Accounting
       operationId: getBatchPayment
       summary: Retrieves a specific batch payment using a unique batch payment Id
       parameters: