[Editorial] Update spec to reference web-based-payment-handler (#1054)

Rather than the old [[[payment-handler]]]. No change on spec text since
the spec database already had corrected for the rename.

Author: stephenmcgruer

index.html

@@ -1147,7 +1147,7 @@ <h2>
                 <aside class="note" title="Payment Handler registration">
                   Mechanisms to register a payment handler are outside the
                   scope of this specification. For one mechanism, see
-                  [[[payment-handler]]].
+                  [[[web-based-payment-handler]]].
                 </aside>
               </li>
               <li>For each |handler| in |registeredHandlers|:
@@ -4430,7 +4430,7 @@ <h2 id="user-info">
           data models used by existing payment methods, prescribing data
           specifics in this API would limit its usefulness. The
           {{PaymentResponse/details}} member carries data from the payment
-          handler, whether Web-based (as defined by the [[[payment-handler]]])
+          handler, whether Web-based (as defined by the [[[web-based-payment-handler]]])
           or proprietary. The [=user agent=] MUST NOT support payment handlers
           unless they include adequate user consent mechanisms (such as
           awareness of parties to the transaction and mechanisms for