mark parameter as required?

It could be useful to have some parameters that don't have a default and aren't able to be given empty values. For instance, I want to have `name` as a parameter, but providing a default value leads people to accidentally create a repo with the default value. Then they either have to rerun it and be a bit more careful, or modify all the strings and files with the incorrect value. If they don't provide a value for name, it creates the project in the current directory, which is surprising and can lead to filling up a parent directory with a bunch of files and folders that have to be cleaned up. Being able to mark name as required would solve both of these cases.