I am happy to add some defaults, but I am not sure what values would work for most users.

What do you propose? What would work for projects created via `bacn`?

This is the structure created by `slc lb project`:

```
{project-root}
   app.js
   public
      {static files}
```

Assuming that `Gruntfile` will be added to the project root, the defaults would be `input: 'app.js'` and `output: 'public/js/lb-services.js'`.