Fixed GetImageFromGallery's callback returning null on Meizu 18X (fixed #348)

Simplified Package Manager installation instruction

Fixed SaveImageToGallery not always truncating the overwritten file (see https://github.com/yasirkula/UnityNativeFilePicker/issues/61)

- BREAKING CHANGE: CheckPermission returns bool instead of Permission (see https://github.com/yasirkula/UnityAndroidRuntimePermissions/issues/14)

Added missing markdown for a code snippet

On Android 33+, it's now possible to preserve access to the picked images after the app is restarted but it isn't recommended (see the relevant FAQ entry)(#328)

Added FAQ entry for standalone platforms

Potential fix for #313 ("No such proxy method" error)

Fixed RequestPermissionAsync not working on iOS

Fixed permission not being asked in an edge case on Android (it's strongly recommended to use RequestPermissionAsync)

Fixed build error if PhotosUI framework was added explicitly on iOS

Potential fix for IllegalStateException on Android

Fixed crash when using LoadImageAtPathAsync on newer Unity versions (fixed #302)

Removed the new READ_MEDIA permissions: https://support.google.com/googleplay/android-developer/answer/13986130

Photo Library Usage Description doesn't override Xcode setting if it's empty