message: update getAccessTokenAsync link
diff: @@ -24,7 +24,7 @@ The following features are in preview.
  - [Office.context.mailbox.item.recurrence](office.context.mailbox.item.md#nullable-recurrence-recurrencejavascriptapioutlookofficerecurrence) - Added a new property that gets or sets an object which provides methods to manage the recurrence pattern of an appointment item. This property can also be used to get the recurrence pattern of a meeting request item.
  - [Office.context.mailbox.item.removeHandlerAsync](office.context.mailbox.item.md#removehandlerasynceventtype-handler-options-callback) - Added a new method that removes an event handler.
  - [Office.context.mailbox.item.seriesId](office.context.mailbox.item.md#nullable-seriesid-string) - Added a new property that gets the id of the series an occurrence belongs to.
  -- [Office.context.auth.getAccessTokenAsync](/javascript/api/office/office.auth#getaccesstokenasync-options--callback-) - Added access to `getAccessTokenAsync`, which allows add-ins to [get an access token](https://docs.microsoft.com/outlook/add-ins/authenticate-a-user-with-an-sso-token) for the Microsoft Graph API.
  +- [Office.context.auth.getAccessTokenAsync](https://docs.microsoft.com/office/dev/add-ins/develop/sso-in-office-add-ins#sso-api-reference) - Added access to `getAccessTokenAsync`, which allows add-ins to [get an access token](https://docs.microsoft.com/outlook/add-ins/authenticate-a-user-with-an-sso-token) for the Microsoft Graph API.
  - [Office.MailboxEnums.Days](/javascript/api/outlook/office.mailboxenums.days) - Added a new enum that specifies the day of week or type of day.
  - [Office.MailboxEnums.Month](/javascript/api/outlook/office.mailboxenums.month) - Added a new enum that specifies the month.
  - [Office.MailboxEnums.RecurrenceTimeZone](/javascript/api/outlook/office.mailboxenums.recurrencetimezone) - Added a new enum that specifies the time zone applied to the recurrence.
  