Callbacks service docs updated

interface/api/payments/bodies/payment.yaml

@@ -1,6 +1,7 @@
 components:
   requestBodies:
     QuotePaymentBody:
+      description: JSON payload used to request a quote for one payment intent.
       required: true
       content:
         application/json:
@@ -8,6 +9,7 @@ components:
             $ref: ../request/payment.yaml#/components/schemas/QuotePaymentRequest
 
     QuotePaymentsBody:
+      description: JSON payload used to request quotes for multiple payment intents.
       required: true
       content:
         application/json:
@@ -15,6 +17,7 @@ components:
             $ref: ../request/payment.yaml#/components/schemas/QuotePaymentsRequest
 
     InitiatePaymentBody:
+      description: JSON payload used to initiate a single payment.
       required: true
       content:
         application/json:
@@ -22,6 +25,7 @@ components:
             $ref: ../request/payment.yaml#/components/schemas/InitiatePaymentRequest
 
     InitiatePaymentsBody:
+      description: JSON payload used to initiate multiple payments from a quote reference.
       required: true
       content:
         application/json: