doc examples in element catalog are outdated

[m4b]

Looks like the docs are out of date for <paper-radio-group> example, e.g.:

<paper-radio-group selected="small">
  <paper-radio-button name="small" label="Small"></paper-radio-button>
  <paper-radio-button name="medium" label="Medium"></paper-radio-button>
  <paper-radio-button name="large" label="Large"></paper-radio-button>
</paper-radio-group>

Setting label doesn't seem to do anything, and demos set the label by putting text in the tag, i.e.:

<paper-radio-button>Label<paper-radio-button>

[notwaldorf]

This was fixed in #17, and should make it to the catalog in its next release.