I tried to add a new improvement, but I can't get it to show up on the workboat's job list. The best leads that I can think of are either the possiblity that I need to make a mod rather than editing the standard gamedata (but my mod gives me only the "load game" option, and then fails to do that) or that I need to make an independent civilopaedia entry (I used the one for cottage) or an independent graphic (I used the one for workshop). The hotkey that I assigned doesn't seem to work either. If someone could please give me some of their expertise and/or past experience with stuff like this, it would be much appreciated!