Specs: default exports to {} rather than document, since it makes writing modules saner

sky/examples/radio.sky

 SKY MODULE - radio button and radio button group
 <!-- accessibility handling not implemented yet, pending mojo service -->
 
-<script>
- module.exports = {};
-</script>
-
 <!-- <radio> -->
 <template id="radio-shadow">
  <style>
   :host { width: 1em; height: 1em; border: solid; background: white; }
   :host[checked] { background: black; }
  </style>
 </template>
 <script>
  module.exports.RadioElement = module.registerElement({
    tagName: 'radio',
@@ skipping 63 matching lines @@
          throw;
        let children = this.getChildNodes();
        for (let child of children)
          if (child instanceof module.exports.RadioElement)
            if (child != radio)
              child.checked = false;
      }
    },
  });
 </script>