Add classes to icon paths.
I'd like to use these icons in draw.io, and I've been following [this](https://www.drawio.com/doc/faq/svg-edit-colours) guide to be able to change the color of the icons in the diagram. However, this requires that the path elements in the icon SVGs have classes attached to them. [This](https://stackoverflow.com/questions/73309145/edit-svg-color-in-draw-io) stackoverflow post explains how to edit the SVGs to make them amenable for color editing.

While I can add these manually, it would be nice if they could be there by default.

Essentially the following changes are necessary (taking `zero.svg` as an example):

Current: 

```svg
<svg width="24" height="24" fill="currentColor" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M11.875 7.75A2.375 2.375 0 0 0 9.5 10.125v3.75a2.375 2.375 0 1 0 4.75 0v-3.75a2.375 2.375 0 0 0-2.375-2.375M8 10.125a3.875 3.875 0 0 1 7.75 0v3.75a3.875 3.875 0 0 1-7.75 0z"/></svg>
```

With classes:

```svg
<svg width="24" height="24" fill="currentColor" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg">
<style type="text/css">
    .primary{fill:#000000;} 
 </style>
<path class="primary" d="M11.875 7.75A2.375 2.375 0 0 0 9.5 10.125v3.75a2.375 2.375 0 1 0 4.75 0v-3.75a2.375 2.375 0 0 0-2.375-2.375M8 10.125a3.875 3.875 0 0 1 7.75 0v3.75a3.875 3.875 0 0 1-7.75 0z"/></svg>
```

Notably, the new `<style>` tag, and the addition of `class=primary` to the path.

Would this be possible?

Thanks!