Actually provide mobile-snapped icons

So the documentation says:

> Spectrum provides two sets of icons, one for desktop and one for mobile, so that the same icon doesn’t need to be manually scaled.

Your current CSS in `sites/spectrum-icons.css`:

```css
.spectrum-Icon--sizeXXS,
.spectrum-Icon--sizeXXS img,
.spectrum-Icon--sizeXXS svg {
height: 0.5625rem;
width: 0.5625rem;
}
...
```

And in the `sites/spectrum-css/spectrum-core-lg.css` I've managed to find the sizes for mobile:

```css
.spectrum-Icon--sizeXXS,
.spectrum-Icon--sizeXXS img,
.spectrum-Icon--sizeXXS svg {
height: 11px;
width: 11px;
}
...
```

However this is just CSS and you know that it's not the same as "providing 2 sets of icons" because the snapping actually means something:

> Desktop icons are snapped to a full pixel, while mobile icons are snapped to up to half a pixel because of screen resolution. On rare occasions, an icon design may be off-center in order to place it exactly on a grid.

----

Also

> Each set contains icons of different sizes such as small, medium, and large.

is not true either because you provide either 36px (in `18` folder) or 48 px (in `24` folder) and then scale them using CSS to match the resolution as best as possible, however in reality, it's job _not done_ by the designer, who must actually provide proper SVGs of something like 18 sm / 24 me / 30 lg twice: one for desktop with full-pixel snapping and then one for mobile with half-pixel snapping in order for what you say on the website to be true.

amiwrong and what is found in `24` folder is meant to be mobile with half-pixel snapping according to

> Spectrum icons come in two sizes: 18 px for desktop scale and 22 px for mobile scale.

The only 22 icons I found are limited collection of express icons in

[spectrum-css-workflow-icons](https://github.com/adobe/spectrum-css-workflow-icons/tree/main)/[dist](https://github.com/adobe/spectrum-css-workflow-icons/tree/main/dist)/[spectrum-css-ccx-workflow-icons](https://github.com/adobe/spectrum-css-workflow-icons/tree/main/dist/spectrum-css-ccx-workflow-icons)/[dist](https://github.com/adobe/spectrum-css-workflow-icons/tree/main/dist/spectrum-css-ccx-workflow-icons/dist)/22/

or was it the case that the mobile icons _used to be_ 22 and now they are 24 and https://spectrum.adobe.com/page/iconography/ needs updating?

The problem with CSS-only scaling is that the icon will appear blurry:

Original: 
Scaled with CSS: 

This is why a different version for mobile-snapping is important however it's kind of been neglected?

Start by comparing the icon sizing documentation with sites/spectrum-icons.css and sites/spectrum-css/spectrum-core-lg.css, then inspect the 18 and 24 folders and the linked workflow-icons dist/22 collection. Determine which mobile-snapped icon sets are expected and whether the iconography documentation also needs correction; done means the repository and its stated desktop/mobile behavior agree.

Written by the indexing model from the issue text.