Update README.md

Author: zihejia

README.md

@@ -88,6 +88,7 @@ You're done! You've successfully integrated the Mixpanel Flutter SDK into your a
 ## 4. Check for Success
 [Open up Events in Mixpanel](https://mixpanel.com/report/events)  to view incoming events.
 Once data hits our API, it generally takes ~60 seconds for it to be processed, stored, and queryable in your project.
+👋 👋  Tell us about the Mixpanel developer experience! [https://www.mixpanel.com/devnps](https://www.mixpanel.com/devnps) 👍  👎
 
 # FAQ