Editorial: Fix types of CalendarExtraFields

This was a straggler from the removal of custom calendars - these should
be enumeration values from the Calendar Fields Record table, not property
keys.

spec/calendar.html

@@ -1265,12 +1265,12 @@ <h1>
       <h1>
         CalendarExtraFields (
           _calendar_: a String that is not *"iso8601"* for which IsBuiltinCalendar returns *true*,
-          _type_: ~date~, ~year-month~, ~month-day~, or a List of property keys,
-        ): a List of property keys
+          _type_: ~date~, ~year-month~, ~month-day~, or a List of values from the Enumeration Key column of <emu-xref href="#table-temporal-calendar-fields-record-fields"></emu-xref>,
+        ): a List of values from the Enumeration Key column of <emu-xref href="#table-temporal-calendar-fields-record-fields"></emu-xref>
       </h1>
       <dl class="header">
         <dt>description</dt>
-        <dd>It characterizes calendar-specific fields that are relevant for values of the provided _type_ in the built-in calendar identified by _calendar_ (inferring the type when _type_ is a List by interpreting its elements as field names). For example, « *"era"*, *"eraYear"* » is returned when _calendar_ is *"gregory"* or *"japanese"* and _type_ is ~date~ or ~year-month~ or a List containing *"year"*.</dd>
+        <dd>It characterizes calendar-specific fields that are relevant for values of the provided _type_ in the built-in calendar identified by _calendar_ (inferring the type when _type_ is a List by interpreting its elements as field names). For example, « ~era~, ~eraYear~ » is returned when _calendar_ is *"gregory"* or *"japanese"* and _type_ is ~date~ or ~year-month~ or a List containing ~year~.</dd>
       </dl>
     </emu-clause>