chore: docs

README.md

@@ -8,6 +8,7 @@ Copy text to the user's clipboard.
 ![Build size Brotli](https://img.badgesize.io/ryangjchandler/alpine-clipboard/master/dist/alpine-clipboard.js.svg?compression=gzip&style=flat-square&color=green)
 [![Monthly downloads via CDN](https://data.jsdelivr.com/v1/package/npm/@ryangjchandler/alpine-clipboard/badge)](https://www.jsdelivr.com/package/npm/@ryangjchandler/alpine-clipboard)
 
+> Since v2.0, this package only supports Alpine v3.x. If you're still using Alpine 2.x, please use [v1.0](https://github.com/ryangjchandler/alpine-clipboard/tree/v1.0.0) of this package.
 ## About
 
 This plugin adds a new `$clipboard` magic property to all of your Alpine components that can be used to copy any piece of data to the user's clipboard.