Tailwind v4 compatibility

[sambauers]

Since Tailwind v4 has now landed with support for 3D utility classes, I won’t be making this plugin compatible with v4.

I will maintain the plugin for a little while for those that can’t upgrade to v4 yet.

I’ll be updating the README soon to make this more visible, and I’ll also provide a guide to move from this plugin to the native Tailwind v4 utility classes.