docs(readme): use aka.ms Playwright Slack invite link (#327)

Author: mxschmitt

README.md

@@ -3,7 +3,7 @@
 [![javadoc](https://javadoc.io/badge2/com.microsoft.playwright/playwright/javadoc.svg)](https://javadoc.io/doc/com.microsoft.playwright/playwright)
 [![maven version](https://img.shields.io/maven-central/v/com.microsoft.playwright/playwright)](https://search.maven.org/search?q=com.microsoft.playwright)
 [![Sonatype Nexus (Snapshots)](https://img.shields.io/nexus/s/https/oss.sonatype.org/com.microsoft.playwright/playwright.svg)](https://oss.sonatype.org/content/repositories/snapshots/com/microsoft/playwright/playwright/)
-[![Join Slack](https://img.shields.io/badge/join-slack-infomational)](https://join.slack.com/t/playwright/shared_invite/enQtOTEyMTUxMzgxMjIwLThjMDUxZmIyNTRiMTJjNjIyMzdmZDA3MTQxZWUwZTFjZjQwNGYxZGM5MzRmNzZlMWI5ZWUyOTkzMjE5Njg1NDg)
+[![Join Slack](https://img.shields.io/badge/join-slack-infomational)](https://aka.ms/playwright-slack)
 
 #### [Website](https://playwright.dev/) | [API reference](https://www.javadoc.io/doc/com.microsoft.playwright/playwright/latest/index.html)