chore: updating readme (#742)

README.md

@@ -1,3 +1,5 @@
+<table><tr><td><p align="center"><b>⚠️ PLEASE READ ⚠️</b></p><p align="center">This package is currently being migrated to our <a href="https://github.com/MetaMask/metamask-design-system"><code>metamask-design-system</code></a> monorepo. Please do not make any commits to this repository while this migration is taking place, as they will not be transferred over. Also, please re-open PRs that are under active development in the @metamask/design-tokens.</p></td></tr></table>
+
 # MetaMask Design Tokens 🪙
 
 [![npm version](https://badge.fury.io/js/@metamask%2Fdesign-tokens.svg)](https://npmjs.com/package/@metamask/design-tokens) [![Storybook](https://cdn.jsdelivr.net/gh/storybookjs/brand@master/badge/badge-storybook.svg)](https://metamask.github.io/design-tokens)