Gruntfile.coffee

// Just the relevant snippet:

copy: 
  assets:
    files: {
       'dist/img': ['img/*'] 
    }
    
// This only creates an empty 'img' dir under 'dist'
// The expected tree to be copied under dist is:
// $ tree img/
// img/
// └── grid_noise
//     ├── grid_noise.png
//     └── readme.txt