Set category ability after starting to mark a edit

[mirror176]

I find it distracting to try to think which times were for what content type after getting to the end of some programs. Having the ability to assign the category would be nice for the edits that aren't too short and would give the submitter something to do then while the undesired content is passing by.

[mirror176]

If implemented, it would be nice to control what a default submission will receive without selecting. Right now it defaults to sponsor. Some users may find that to not be their primary submission type and could change it. I would prefer to not have it set by default but require that I pick a setting before submission can complete to make sure I don't accidentally submit as a sponsor from a misclicked/rushed/forgotton+overlooked posting.