Add phone and email fields to administrative office pages

[bwaltz]

Office Detail is the field group name. We'll need to create two new fields, phone and email, and build support for those field values in twig.

[bwaltz]

@GioAceto There may already be twig support for those fields, just judging from https://github.com/ColbyCommunications/colby-college-theme/blob/master/src/twig/pages/single-office.twig#L30

So maybe all we need to do is add the fields and it will just work.