It's pretty much what is below. The html template is generated by turtle instead of the user having to provide it:

 +  turtle.template({
 +    name: 'templateName',
 +    css: [
 +      'maybe/a/path/to/mocha.css'
 +    ],
 +    scripts: [
 +      '../path/to/my/included/library.js',
 +      './another/path/to/another/lib.js'
 +    ]
 +  })

It allows to have all the paths and copy paste them into some temp directory. gives us more flexibility in how we can extends tests and environment definitions.