Polymorphism is your friend - definitely subclass! This way you can define an output method and just call it on which ever object you instantiated.
Why? That way suggests that an ‘HTML resumé’ is an inherently different kind of thing to a ‘PDF resumeé᾿, that they are distinct classes of object in the same way that camels and llamas are distinct. (Well, OK, not in quite the same way.)
I reckon the opposite is true — there isn't such a thing as an ‘HTML resumeé’ or a ‘PDF resumeé’ in terms of what it models. You can have a resumé which contains data representing your personal details and work history. You can do several things with that data, including emitting it in particular output formats.
But it seems daft to have a object which in effect means “the data in this instance represents my life achievements but it can only be displayed as a PDF” and forcing you to copy the data to another instance just because you want it to be emitted differently.