Cover letters
One letter per CV, drafted from your own experience and the posting.
The letter lives on the CV rather than in a library of its own, because a cover letter is only ever for one application — same facts, same posting, same employer.
On the Letter tab you can draft one, or open an empty editor and write it yourself. A draft is written from your CV and the posting on it and nothing else, and the notes underneath are the model's own account of what it could not do.