Yes. In your class config you can tell proji to create a file in the new project based on a given template. Templates are stored in '~/.config/proji/templates' and can be of any type(txt, py, go,..). In addition, proji can execute shell scripts, which practically offers unlimited possibilities.
For more information about files, scripts and templates you may read this part of the docs: https://github.com/nikoksr/proji#setting-up-a-class-