Allow uploading pdfs when resubmitting.
When writing Comments and replying to them, as well as when replying to Referee Reports, there exists the option to attach a file. I find this very useful, because it allows me to attach a pdf of the comment/reply, which is often better formatted than the textbox on the website. However, the option to attach a file is missing from the resubmission page. It would be very helpful to allow authors to upload a pdf of their resubmission letter, since the higher-quality formatting would allow for easier reading, especially when there are many questions to answer. Right now my workaround is to either paste a link to the reply pdf uploaded to an external site, such as Dropbox, or separately upload the reply pdf as a comment and mention in the resubmission that the comment is actually the reply.