GMail Script not accepting trailing comas

[pierrelocus]

Hi,

After using the script today for GMail, I got errors with the built file.
When trying to copy paste it on the Apps Script, we get an error (a second time when the first is fixed), because of trailing comas:

Once we remove the trailing comas, we can save the file without errors:

Unless it's required for Outlook (would be strange), I make a PR to fix that in the prettierrc.

Regards