Update README.md

Author: richgel999

README.md

@@ -5,6 +5,8 @@ Basis Universal Supercompressed GPU Texture Codec
 
 [![Build status](https://ci.appveyor.com/api/projects/status/87eb0o96pjho4sh0?svg=true)](https://ci.appveyor.com/project/BinomialLLC/basis-universal)
 
+Note: UASTC HDR support (for native and WebAssembly) is coming in early September.
+
 Basis Universal is a ["supercompressed"](http://gamma.cs.unc.edu/GST/gst.pdf) GPU texture data interchange system that supports two highly compressed intermediate file formats (.basis or the [.KTX2 open standard from the Khronos Group](https://github.khronos.org/KTX-Specification/)) that can be quickly transcoded to a [very wide variety](https://github.com/BinomialLLC/basis_universal/wiki/OpenGL-texture-format-enums-table) of GPU compressed and uncompressed pixel formats: ASTC 4x4 L/LA/RGB/RGBA, PVRTC1 4bpp RGB/RGBA, PVRTC2 RGB/RGBA, BC7 mode 6 RGB, BC7 mode 5 RGB/RGBA, BC1-5 RGB/RGBA/X/XY, ETC1 RGB, ETC2 RGBA, ATC RGB/RGBA, ETC2 EAC R11 and RG11, FXT1 RGB, and uncompressed raster image formats 8888/565/4444. 
 
 The system now supports two modes: a high quality mode which is internally based off the [UASTC compressed texture format](https://richg42.blogspot.com/2020/01/uastc-block-format-encoding.html), and the original lower quality mode which is based off a subset of ETC1 called "ETC1S". UASTC is for extremely high quality (similar to BC7 quality) textures, and ETC1S is for very small files. The ETC1S system includes built-in data compression, while the UASTC system includes an optional Rate Distortion Optimization (RDO) post-process stage that conditions the encoded UASTC texture data in the .basis file so it can be more effectively LZ compressed by the end user. More technical details about UASTC integration are [here](https://github.com/BinomialLLC/basis_universal/wiki/UASTC-implementation-details).