Missing icon for .ps files

[wforney]

A .ps file is either of these:

1. https://www.adobe.com/creativecloud/file-types/image/vector/ps-file.html
2. https://learn.microsoft.com/en-us/windows/uwp/graphics-concepts/pixel-shader-stage--ps-

In my use case it usually is a pixel shader in VS, but it could be the other as well. YMMV