support svg elements/properties

I have been working more with svg elements lately (with d3.js) and having half my stylesheets highlighted as error is really annoying.
is there a version of this bundle supporting svg and if not would a pull request to add svg support be accepted ?

here is an example of svg stylesheet:
```css
line {
  fill: none;
  stroke-width: 2px;
  stroke: black;
}
```

here both "stroke" and "stroke-width" and it would be true if it was html but it is not :(