Add Product Hunt launch badge

Embed the Product Hunt "Featured" badge for the NativeAppTemplate 2.0
launch so visitors can see the live ranking and upvote directly.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: dadachi

README.md

@@ -1,5 +1,7 @@
 # NativeAppTemplate-Free-Android
 
+<a href="https://www.producthunt.com/products/nativeapptemplate?embed=true&utm_source=badge-featured&utm_medium=badge&utm_campaign=badge-nativeapptemplate-2-0" target="_blank"><img src="https://api.producthunt.com/widgets/embed-image/v1/featured.svg?post_id=1124956&theme=light" alt="NativeAppTemplate 2.0 - Native iOS + Android + Rails boilerplate, now open source | Product Hunt" width="250" height="54" /></a>
+
 NativeAppTemplate-Free-Android is a modern, comprehensive, and production-ready native Android app with user authentication and [background tag reading](https://developer.android.com/develop/connectivity/nfc/nfc).  
 This Android app is a free version of  [NativeAppTemplate-Android (Solo)](https://nativeapptemplate.com/products/android-solo) and [NativeAppTemplate-Android (Team)](https://nativeapptemplate.com/products/android-team).