docs structure field highlight

Stream: general

[Winston Yin (尹維晨)]

I must've missed when this change on the docs site happened, but I'd just like to say how much I love that inherited fields are now muted in colour compared to fields added by the current definition. It makes reading Module and ModelWithCorners much less of a chore! Here's a poor man's medal to whomever implemented this: :gold:

[Henrik Böving]

@Kyle Miller