Open-source grid and sliders (ygit#12)

* Open-source grid and sliders

* Update README.md

Author: ay42

README.md

@@ -173,3 +173,7 @@
 
 28. 📖 [SwiftUIHub:Resources for swiftUI](https://swiftuihub.com/)
 
+29. 💻 [SwiftUI Sliders](https://github.com/SwiftUIExtensions/Sliders)
+
+30. 💻 [SwiftUI Grid](https://github.com/SwiftUIExtensions/Grid)
+