What do you think of this idea?

```coffeescript
doctest = require 'doctest'

doctest 'foo.js'  # test foo.js with the default options

runner = new doctest.TestRunner module: yes
runner.test 'bar.js', 'baz.js'  # test bar.js and baz.js with `module: yes`
```

The doctest function might look something like the following:

```coffeescript
doctest = (urls...) ->
  runner = new TestRunner {}
  callback = _.bind runner.test, runner
  _.each urls, (url) -> fetch url, callback
```

The hard-coded calls to doctest.run in the fetch function might need to be removed.