message: Update status-page link in README
diff: <p align="center">
  <a href="https://reddit.com/r/setup_php" title="setup-php reddit"><img alt="setup-php reddit" src="https://img.shields.io/badge/reddit-join-FF5700?logo=reddit&logoColor=FF5700&labelColor=555555"></a>
  <a href="https://twitter.com/setup_php" title="setup-php twitter"><img alt="setup-php twitter" src="https://img.shields.io/badge/twitter-follow-1DA1F2?logo=twitter&logoColor=1DA1F2&labelColor=555555"></a>
  - <a href="https://setup-php.statuspage.io/" title="setup-php status"><img alt="setup-php status" src="https://img.shields.io/badge/status-subscribe-28A745?logo=statuspage&logoColor=28A745&labelColor=555555"></a>
  + <a href="https://status.setup-php.com" title="setup-php status"><img alt="setup-php status" src="https://img.shields.io/badge/status-subscribe-28A745?logo=statuspage&logoColor=28A745&labelColor=555555"></a>
  </p>
  Setup PHP with required extensions, php.ini configuration, code-coverage support and various tools like composer in [GitHub Actions](https://github.com/features/actions "GitHub Actions"). This action gives you a cross platform interface to set up the PHP environment you need to test your application. Refer to [Usage](#memo-usage "How to use this") section and [examples](#examples "Examples of use") to see how to use this.
  