docs: update link to Slack invite (#69)

Author: gregorwolf

README.md

@@ -148,7 +148,7 @@ Keep in mind that linking the same module with npm and Yarn may cause issues. Al
 No major bugs known.
 
 ## Support
-We welcome all comments, suggestions, questions, and bug reports. Please follow our [Support Guidelines](/SUPPORT.md#-content) on how to report an issue, or chat with us in the `#webcomponents` channel of the [OpenUI5 Community Slack](https://join-ui5-slack.herokuapp.com/).
+We welcome all comments, suggestions, questions, and bug reports. Please follow our [Support Guidelines](/SUPPORT.md#-content) on how to report an issue, or chat with us in the `#webcomponents` channel of the [OpenUI5 Community Slack](https://ui5-slack-invite.cfapps.eu10.hana.ondemand.com/).
 
 ## Contribute
 Please check our [Contribution Guidelines](/CONTRIBUTING.md).