chore: remove link to Slack

Author: igorlukanin

website/docs/index.mdx

@@ -91,6 +91,6 @@ Please check "[Chart.js Example with Dynamic Dataset](https://cube.dev/blog/char
 
 ## Getting Help
 
-Need help? Ask your question on [Slack](https://slack.cube.dev/?ref=eco-react-chartjs) or [Stack Overflow](https://stackoverflow.com/questions/tagged/react-chartjs-2).
+Need help? Ask your question on [Stack Overflow](https://stackoverflow.com/questions/tagged/react-chartjs-2).
 
 If you've encountered an issue, please [file it on GitHub](https://github.com/reactchartjs/react-chartjs-2/issues).