Add simple file browser properly

Packages/manifest.json

@@ -21,6 +21,7 @@
     "com.unity.toolchain.macos-arm64-linux": "1.0.2",
     "com.unity.ugui": "2.0.0",
     "com.unity.visualscripting": "1.9.9",
+    "com.yasirkula.simplefilebrowser": "https://github.com/yasirkula/UnitySimpleFileBrowser.git",
     "com.unity.modules.accessibility": "1.0.0",
     "com.unity.modules.adaptiveperformance": "1.0.0",
     "com.unity.modules.ai": "1.0.0",