Support negative session targets

Basically, at the editing stage there are often times where my goal is not to produce more words, but actually to cut a certain amount of words in order to get to the required word count for a document. I would like the ability to set a goal of how many words I’ve cut, rather than added. I know I can still track it but it would nice to see that nice progress fill up rather than go down for every darling I kill :slight_smile: