Add default json config project to new project

Hi Erik, I think the music you've made with pippi is really great, and since you've kindly made this open source I wanted to check it out.

With pippi-console, I tried following along with your Read The Docs example, but "pippi new acoolproject" didn't create a default pippi json file for the project, so I kept getting an IOException and couldn't use the tool.

I looked at init_config() in settings.py, and you have a comment about creating a default config file if one doesn't exist. I added a few lines that create a default, and now the example works for me (and it's really cool).

Feel free to merge this in, or ignore it if you understandably don't want my grimy hands touching your repository!