Hello! My name is Hannah, and I am hoping to contribute to Popper. I was trying to install Popper to learn about how it works and all before trying to work on it, and I am getting an odd error. When I run the command "popper --help" it says "Error: Command 'add' doesn't exist." I am not sure where to look to figure out how to fix this issue. Indeed, if I try to use "popper add" it brings up an error message, but if I try to use another command such as "popper scaffold" it will work properly. Has anyone else encountered this problem?