message: Update README.md badges
diff: <br>
  <p align="center">
  - <a href="https://npmjs.org/package/ariakit"><img alt="NPM version" src="https://img.shields.io/npm/v/ariakit.svg" /></a>
  - <a href="https://npmjs.org/package/ariakit"><img alt="NPM downloads" src="https://img.shields.io/npm/dm/ariakit.svg"></a>
  - <a href="https://github.com/ariakit/ariakit/actions"><img alt="Build Status" src="https://github.com/ariakit/ariakit/workflows/ci/badge.svg?event=push&branch=main" /></a>
  - <a href="https://codecov.io/gh/ariakit/ariakit"><img src="https://codecov.io/gh/ariakit/ariakit/branch/main/graph/badge.svg" /></a><br>
  - <a href="https://opencollective.com/ariakit"><img alt="Sponsors" src="https://opencollective.com/ariakit/sponsor/badge.svg?label=sponsors" /></a>
  - <a href="https://opencollective.com/ariakit"><img alt="Backers" src="https://opencollective.com/ariakit/backer/badge.svg?label=backers" /></a>
  + <a href="https://npmjs.org/package/ariakit">
  + <img alt="NPM version" src="https://img.shields.io/npm/v/ariakit.svg?logo=npm&color=007acc" />
  + </a>
  + <a href="https://github.com/ariakit/ariakit/releases">
  + <img alt="GitHub (Pre-)Release Date" src="https://img.shields.io/github/release-date-pre/ariakit/ariakit?logo=github&color=007acc">
  + </a>
  + <a href="https://github.com/ariakit/ariakit/discussions">
  + <img alt="GitHub Discussions" src="https://img.shields.io/github/discussions/ariakit/ariakit?logo=github&color=007acc">
  + </a>
  + <br>
  + <a href="https://npmjs.org/package/ariakit">
  + <img alt="NPM downloads" src="https://img.shields.io/npm/dm/ariakit.svg?logo=npm&style=social">
  + </a>
  + &nbsp;
  + <a href="https://github.com/ariakit/ariakit/stargazers">
  + <img alt="GitHub Repo stars" src="https://img.shields.io/github/stars/ariakit/ariakit?style=social">
  + </a>
  + &nbsp;
  <a href="https://twitter.com/ariakitjs">
  - <img alt="Follow Ariakit on Twitter" src="https://img.shields.io/twitter/follow/ariakitjs.svg"></a>
  + <img alt="Follow Ariakit on Twitter" src="https://img.shields.io/twitter/follow/ariakitjs.svg">
  + </a>
  </p>
  > **Note**: This is the Ariakit (v2) branch <sup>[<a href="https://gist.github.com/diegohaz/bc07491aee61a5f2469574b38c5c1aa0">What is Ariakit?</a>]</sup>, which is still in alpha.
  