Add GitHub Sponsors metadata

Author: lostf1sh

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: [lostf1sh]

README.md

@@ -19,6 +19,9 @@
   <a href="https://github.com/lostf1sh/PixelPlayerOSS/releases">
     <img src="https://img.shields.io/github/downloads/lostf1sh/PixelPlayerOSS/total?logo=github&style=for-the-badge" alt="Total downloads">
   </a>
+  <a href="https://github.com/sponsors/lostf1sh">
+    <img src="https://img.shields.io/badge/Sponsor-GitHub%20Sponsors-EA4AAA?style=for-the-badge&logo=githubsponsors&logoColor=white" alt="Sponsor on GitHub Sponsors">
+  </a>
   <img src="https://img.shields.io/badge/Android-11%2B-3DDC84?style=for-the-badge&logo=android&logoColor=white" alt="Android 11+">
   <img src="https://img.shields.io/badge/License-GPLv3-blue?style=for-the-badge" alt="GPLv3 license">
 </p>
@@ -144,6 +147,10 @@ F-Droid listing metadata lives in `fastlane/metadata/android/en-US`; build/relea
 
 > Note: F-Droid builds and signs its own APKs from source, so they may lag behind GitHub releases while the new version works through the F-Droid build cycle. F-Droid and GitHub APK signatures differ — switching between the two requires an uninstall/reinstall.
 
+## Support
+
+If PixelPlayerOSS is useful to you, you can support ongoing development through [GitHub Sponsors](https://github.com/sponsors/lostf1sh).
+
 ## Project Structure
 
 ```text