docs(plugin-legacy): fix Vite default target (#10158)

Author: sapphi-red

packages/plugin-legacy/README.md

@@ -1,6 +1,6 @@
 # @vitejs/plugin-legacy [![npm](https://img.shields.io/npm/v/@vitejs/plugin-legacy.svg)](https://npmjs.com/package/@vitejs/plugin-legacy)
 
-Vite's default browser support baseline is [Native ESM](https://caniuse.com/es6-module). This plugin provides support for legacy browsers that do not support native ESM when building for production.
+Vite's default browser support baseline is [Native ESM](https://caniuse.com/es6-module), [native ESM dynamic import](https://caniuse.com/es6-module-dynamic-import), and [`import.meta`](https://caniuse.com/mdn-javascript_operators_import_meta). This plugin provides support for legacy browsers that do not support those features when building for production.
 
 By default, this plugin will: