message: add className to docs
diff: @@ -77,6 +77,13 @@ title: SVG
  </td>
  <td>Separate</td>
  </tr>
  + <tr>
  + <td><a href="/docs/api/interfaces/makerjs.exporter.isvgrenderoptions.html#className">className</a></td>
  + <td>
  + string - Class name
  + </td>
  + <td>Both</td>
  + </tr>
  <tr>
  <td><a href="/docs/api/interfaces/makerjs.exporter.isvgrenderoptions.html#cssstyle">cssStyle</a></td>
  <td>
  @@ -118,6 +125,12 @@ title: SVG
  <th>property</th>
  <th>values</th>
  </tr>
  + <tr>
  + <td><a href="/docs/api/interfaces/makerjs.exporter.isvgelementrenderoptions.html#className">className</a></td>
  + <td>
  + string - Class name
  + </td>
  + </tr>
  <tr>
  <td><a href="/docs/api/interfaces/makerjs.exporter.isvgelementrenderoptions.html#cssstyle">cssStyle</a></td>
  <td>
  