Adding text to the README that enviornment depth and occlusion is supported on certain iOS devices.

README.md

 ## DepthImages
 
 This sample demonstrates raw texture depth images from different methods.
-* Environment depth (certain Android devices)
+* Environment depth (certain Android devices and Apple devices with the LiDAR sensor)
-This sample demonstrates occlusion of virtual content by real world content through the use of environment depth images on supported Android devices.
+This sample demonstrates occlusion of virtual content by real world content through the use of environment depth images on supported Android and iOS devices.
 
 ## AllPointCloudPoints